CVE-2026-105274 (GCVE-0-2026-105274)
Vulnerability from cvelistv5 – Published: 2026-10-12 16:43 – Updated: 2026-10-12 18:16
VLAI
EPSS
VEX
Title
hex_core decompresses registry and Erlang term API responses without size limits
Summary
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in hexpm hex_core allows an untrusted repository mirror, or a server answering hex_core's API requests, to exhaust the memory of the Erlang VM running hex_core. The same code is vendored in Hex (mix_hex_repo, mix_hex_api) and rebar3 (r3_hex_repo, r3_hex_api).
hex_repo:get_names/1, hex_repo:get_versions/1, hex_repo:get_package/2 and hex_repo:get_policy/2 decompress the registry response with zlib:gunzip/1 and decode the signed envelope before verifying its signature. A mirror doesn't have the repository's private key, but it chooses the compressed bytes, so a small response decompresses into an envelope of any size before the signature check rejects it.
hex_api decodes responses with the application/vnd.hex+erlang content type through hex_safe_binary_to_term:safe_binary_to_term/1, which calls binary_to_term(Binary, [safe]). The safe option prevents atom creation, but it accepts compressed terms and doesn't limit the size of the decoded term, and the check that rejects functions and ports runs after the term has been built. The fix for CVE-2026-21619 added the safe option and that check without bounding the decoded size.
This issue affects rebar3: from 3.9.1 before 3.27.3; hex: from 2.1.0 before 2.5.2; hex_core: from 0.1.0 before 0.20.0.
Severity
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
9 references
Impacted products
6 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| erlang | rebar3 |
Affected:
3.9.1 , < 3.27.3
(semver)
cpe:2.3:a:erlang:rebar3:*:*:*:*:*:*:*:* |
||
| erlang | rebar3 |
Affected:
209c02ec57c2cc3207ee0174c3af3675b8dc8f79 , < 360838a22f5b3a88c0358207f2923059bcbb3afb
(git)
cpe:2.3:a:erlang:rebar3:*:*:*:*:*:*:*:* |
||
| hexpm | hex_core |
Affected:
0.1.0 , < 0.20.0
(semver)
cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:* |
||
| hexpm | hex_core |
Affected:
fbb6d9de472e5edb8d6fb6b32a91cb266137892e , < ebe25d110717f6a3addba5232cd4a7dc1c76b628
(git)
cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:* |
||
| hexpm | hex |
Affected:
2.1.0 , < 2.5.2
(semver)
cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:* |
||
| hexpm | hex |
Affected:
671f695ac548ed01f5828c2a739ecaa942b21007 , < d8b60eee97abb119d525306f048969a217d793a5
(git)
cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:* |
Date Public
2026-10-12 16:43
{
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{
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{
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"repo": "https://github.com/hexpm/hex_core",
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{
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{
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"repo": "https://github.com/hexpm/hex_core",
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"versions": [
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"modules": [
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],
"packageName": "hex",
"packageURL": "pkg:otp/hex?repository_url=https:%2F%2Fgithub.com%2Fhexpm%2Fhex\u0026vcs_url=repository_url=git%2Bhttps:%2F%2Fgithub.com%2Fhexpm%2Fhex.git",
"product": "hex",
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{
"name": "mix_hex_repo:get_policy/2"
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{
"name": "mix_hex_api:request/4"
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],
"repo": "https://github.com/hexpm/hex",
"vendor": "hexpm",
"versions": [
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"status": "affected",
"version": "2.1.0",
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"cpes": [
"cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"mix_hex_repo",
"mix_hex_api"
],
"packageName": "hexpm/hex",
"packageURL": "pkg:github/hexpm/hex",
"product": "hex",
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"src/mix_hex_repo.erl",
"src/mix_hex_api.erl"
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"configurations": [
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"supportingMedia": [
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"type": "text/html",
"value": "\u003cp\u003eRegistry decoding is affected when a repository\u0027s URL points at a mirror or another server the user doesn\u0027t trust with the availability of their builds, for example Hex\u0027s \u003ccode\u003eHEX_MIRROR_URL\u003c/code\u003e or \u003ccode\u003emirror_url\u003c/code\u003e and rebar3\u0027s \u003ccode\u003eHEX_MIRROR_URL\u003c/code\u003e. API decoding is affected when the API URL points at such a server or an attacker can alter API responses. Requests to repo.hex.pm and hex.pm over verified HTTPS aren\u0027t affected.\u003c/p\u003e"
},
{
"base64": false,
"type": "text/markdown",
"value": "Registry decoding is affected when a repository\u0027s URL points at a mirror or another server the user doesn\u0027t trust with the availability of their builds, for example Hex\u0027s `HEX_MIRROR_URL` or `mirror_url` and rebar3\u0027s `HEX_MIRROR_URL`. API decoding is affected when the API URL points at such a server or an attacker can alter API responses. Requests to repo.hex.pm and hex.pm over verified HTTPS aren\u0027t affected."
}
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"value": "Registry decoding is affected when a repository\u0027s URL points at a mirror or another server the user doesn\u0027t trust with the availability of their builds, for example Hex\u0027s HEX_MIRROR_URL or mirror_url and rebar3\u0027s HEX_MIRROR_URL. API decoding is affected when the API URL points at such a server or an attacker can alter API responses. Requests to repo.hex.pm and hex.pm over verified HTTPS aren\u0027t affected."
}
],
"cpeApplicability": [
{
"nodes": [
{
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{
"criteria": "cpe:2.3:a:erlang:rebar3:*:*:*:*:*:*:*:*",
"versionEndExcluding": "3.27.3",
"versionStartIncluding": "3.9.1",
"vulnerable": true
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{
"criteria": "cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:*",
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{
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"credits": [
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"type": "finder",
"value": "Peter Ullrich"
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{
"lang": "en",
"type": "remediation developer",
"value": "Eric Meadows-J\u00f6nsson"
},
{
"lang": "en",
"type": "analyst",
"value": "Jonatan M\u00e4nnchen / EEF"
}
],
"dateAssigned": "2026-10-10T13:01:00.000Z",
"datePublic": "2026-10-12T16:43:59.000Z",
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"supportingMedia": [
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"value": "\u003cp\u003eImproper Handling of Highly Compressed Data (Data Amplification) vulnerability in hexpm hex_core allows an untrusted repository mirror, or a server answering hex_core\u0027s API requests, to exhaust the memory of the Erlang VM running hex_core. The same code is vendored in Hex (\u003ccode\u003emix_hex_repo\u003c/code\u003e, \u003ccode\u003emix_hex_api\u003c/code\u003e) and rebar3 (\u003ccode\u003er3_hex_repo\u003c/code\u003e, \u003ccode\u003er3_hex_api\u003c/code\u003e).\u003c/p\u003e\n\u003cp\u003e\u003ccode\u003ehex_repo:get_names/1\u003c/code\u003e, \u003ccode\u003ehex_repo:get_versions/1\u003c/code\u003e, \u003ccode\u003ehex_repo:get_package/2\u003c/code\u003e and \u003ccode\u003ehex_repo:get_policy/2\u003c/code\u003e decompress the registry response with \u003ccode\u003ezlib:gunzip/1\u003c/code\u003e and decode the signed envelope before verifying its signature. A mirror doesn\u0027t have the repository\u0027s private key, but it chooses the compressed bytes, so a small response decompresses into an envelope of any size before the signature check rejects it.\u003c/p\u003e\n\u003cp\u003e\u003ccode\u003ehex_api\u003c/code\u003e decodes responses with the \u003ccode\u003eapplication/vnd.hex+erlang\u003c/code\u003e content type through \u003ccode\u003ehex_safe_binary_to_term:safe_binary_to_term/1\u003c/code\u003e, which calls \u003ccode\u003ebinary_to_term(Binary, [safe])\u003c/code\u003e. The \u003ccode\u003esafe\u003c/code\u003e option prevents atom creation, but it accepts compressed terms and doesn\u0027t limit the size of the decoded term, and the check that rejects functions and ports runs after the term has been built. The fix for CVE-2026-21619 added the \u003ccode\u003esafe\u003c/code\u003e option and that check without bounding the decoded size.\u003c/p\u003e\n\u003cp\u003eThis issue affects rebar3: from 3.9.1 before 3.27.3; hex: from 2.1.0 before 2.5.2; hex_core: from 0.1.0 before 0.20.0.\u003c/p\u003e"
},
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"value": "Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in hexpm hex_core allows an untrusted repository mirror, or a server answering hex_core\u0027s API requests, to exhaust the memory of the Erlang VM running hex_core. The same code is vendored in Hex (`mix_hex_repo`, `mix_hex_api`) and rebar3 (`r3_hex_repo`, `r3_hex_api`).\n\n`hex_repo:get_names/1`, `hex_repo:get_versions/1`, `hex_repo:get_package/2` and `hex_repo:get_policy/2` decompress the registry response with `zlib:gunzip/1` and decode the signed envelope before verifying its signature. A mirror doesn\u0027t have the repository\u0027s private key, but it chooses the compressed bytes, so a small response decompresses into an envelope of any size before the signature check rejects it.\n\n`hex_api` decodes responses with the `application/vnd.hex+erlang` content type through `hex_safe_binary_to_term:safe_binary_to_term/1`, which calls `binary_to_term(Binary, [safe])`. The `safe` option prevents atom creation, but it accepts compressed terms and doesn\u0027t limit the size of the decoded term, and the check that rejects functions and ports runs after the term has been built. The fix for CVE-2026-21619 added the `safe` option and that check without bounding the decoded size.\n\nThis issue affects rebar3: from 3.9.1 before 3.27.3; hex: from 2.1.0 before 2.5.2; hex_core: from 0.1.0 before 0.20.0."
}
],
"value": "Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in hexpm hex_core allows an untrusted repository mirror, or a server answering hex_core\u0027s API requests, to exhaust the memory of the Erlang VM running hex_core. The same code is vendored in Hex (mix_hex_repo, mix_hex_api) and rebar3 (r3_hex_repo, r3_hex_api).\n\nhex_repo:get_names/1, hex_repo:get_versions/1, hex_repo:get_package/2 and hex_repo:get_policy/2 decompress the registry response with zlib:gunzip/1 and decode the signed envelope before verifying its signature. A mirror doesn\u0027t have the repository\u0027s private key, but it chooses the compressed bytes, so a small response decompresses into an envelope of any size before the signature check rejects it.\n\nhex_api decodes responses with the application/vnd.hex+erlang content type through hex_safe_binary_to_term:safe_binary_to_term/1, which calls binary_to_term(Binary, [safe]). The safe option prevents atom creation, but it accepts compressed terms and doesn\u0027t limit the size of the decoded term, and the check that rejects functions and ports runs after the term has been built. The fix for CVE-2026-21619 added the safe option and that check without bounding the decoded size.\n\nThis issue affects rebar3: from 3.9.1 before 3.27.3; hex: from 2.1.0 before 2.5.2; hex_core: from 0.1.0 before 0.20.0."
}
],
"impacts": [
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"value": "\u003cp\u003eA mirror can make every registry fetch allocate memory far beyond the size of its response: in a test against Hex main 851b938, which vendors this code, a 65 KB registry response decompressed into a 64 MiB envelope before the signature check failed. The API server, or an attacker who can alter its responses, can do the same with API responses: 8 KB of compressed Erlang term format decoded into a list of 4.2 million elements. Large enough responses stop the Erlang VM, which fails the build tool command or the program using hex_core. No package code has to run.\u003c/p\u003e"
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"value": "A mirror can make every registry fetch allocate memory far beyond the size of its response: in a test against Hex main 851b938, which vendors this code, a 65 KB registry response decompressed into a 64 MiB envelope before the signature check failed. The API server, or an attacker who can alter its responses, can do the same with API responses: 8 KB of compressed Erlang term format decoded into a list of 4.2 million elements. Large enough responses stop the Erlang VM, which fails the build tool command or the program using hex_core. No package code has to run."
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}
]
}
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"metrics": [
{
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"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
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"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"baseScore": 2.1,
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"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
"version": "4.0",
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"description": "CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)",
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"providerMetadata": {
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"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"shortName": "EEF"
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"references": [
{
"name": "GitHub Advisory",
"tags": [
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"url": "https://github.com/hexpm/hex_core/security/advisories/GHSA-7c4r-cgf9-9jmq"
},
{
"name": "EEF CNA record for CVE-2026-105274",
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"url": "https://cna.erlef.org/cves/CVE-2026-105274.html"
},
{
"name": "OSV record EEF-CVE-2026-105274",
"tags": [
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],
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-105274"
},
{
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{
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"url": "https://github.com/erlang/rebar3/commit/360838a22f5b3a88c0358207f2923059bcbb3afb"
},
{
"name": "Introducing commit fbb6d9d in hexpm/hex_core",
"tags": [
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"url": "https://github.com/hexpm/hex_core/commit/fbb6d9de472e5edb8d6fb6b32a91cb266137892e"
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{
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{
"name": "Introducing commit 671f695 in hexpm/hex",
"tags": [
"related"
],
"url": "https://github.com/hexpm/hex/commit/671f695ac548ed01f5828c2a739ecaa942b21007"
},
{
"name": "Fix commit d8b60ee in hexpm/hex",
"tags": [
"patch"
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"url": "https://github.com/hexpm/hex/commit/d8b60eee97abb119d525306f048969a217d793a5"
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],
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"base64": false,
"type": "text/html",
"value": "\u003cp\u003eUpgrade hex_core to 0.20.0 or later. Registry resources larger than 16 MiB after decompression are rejected with \u003ccode\u003e{too_big_uncompressed, MaxSize}\u003c/code\u003e, configurable with \u003ccode\u003eregistry_max_uncompressed_size\u003c/code\u003e.\u003c/p\u003e\n\u003cp\u003eUpgrade Hex to 2.5.2 or later, which vendors hex_core 0.20.0. No rebar3 release vendors hex_core 0.20.0 yet.\u003c/p\u003e"
},
{
"base64": false,
"type": "text/markdown",
"value": "Upgrade hex_core to 0.20.0 or later. Registry resources larger than 16 MiB after decompression are rejected with `{too_big_uncompressed, MaxSize}`, configurable with `registry_max_uncompressed_size`.\n\nUpgrade Hex to 2.5.2 or later, which vendors hex_core 0.20.0. No rebar3 release vendors hex_core 0.20.0 yet."
}
],
"value": "Upgrade hex_core to 0.20.0 or later. Registry resources larger than 16 MiB after decompression are rejected with {too_big_uncompressed, MaxSize}, configurable with registry_max_uncompressed_size.\n\nUpgrade Hex to 2.5.2 or later, which vendors hex_core 0.20.0. No rebar3 release vendors hex_core 0.20.0 yet."
}
],
"source": {
"discovery": "UNKNOWN"
},
"title": "hex_core decompresses registry and Erlang term API responses without size limits",
"workarounds": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003ePoint repository URLs at repo.hex.pm or a mirror you operate, and the API URL at hex.pm.\u003c/p\u003e"
},
{
"base64": false,
"type": "text/markdown",
"value": "Point repository URLs at repo.hex.pm or a mirror you operate, and the API URL at hex.pm."
}
],
"value": "Point repository URLs at repo.hex.pm or a mirror you operate, and the API URL at hex.pm."
}
],
"x_proofOfConcept": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003col\u003e\n\u003cli\u003ePoint a repository at a loopback mirror (in Hex, \u003ccode\u003eHEX_MIRROR_URL\u003c/code\u003e) that answers \u003ccode\u003e/packages/probe\u003c/code\u003e with a 65,268-byte gzip stream decompressing to a 67,108,872-byte signed envelope with a 64 MiB payload and a one-byte signature.\u003c/li\u003e\n\u003cli\u003e\u003ccode\u003eHex.Repo.get_package(\"hexpm\", \"probe\", nil)\u003c/code\u003e, which calls the vendored \u003ccode\u003ehex_repo:get_package/2\u003c/code\u003e, returns \u003ccode\u003e{:error, :bad_signature}\u003c/code\u003e after allocating the envelope. Peak RSS was 234 MiB, against 96 MiB for a 1,030-byte invalid envelope.\u003c/li\u003e\n\u003cli\u003eAnswer an API request with \u003ccode\u003econtent-type: application/vnd.hex+erlang\u003c/code\u003e and 8,178 bytes of compressed Erlang term format encoding a list of 4,194,304 elements. \u003ccode\u003emix_hex_api:get/2\u003c/code\u003e accepts the decoded term, and BEAM memory rises from 58 MiB to 272 MiB.\u003c/li\u003e\n\u003c/ol\u003e"
},
{
"base64": false,
"type": "text/markdown",
"value": "1. Point a repository at a loopback mirror (in Hex, `HEX_MIRROR_URL`) that answers `/packages/probe` with a 65,268-byte gzip stream decompressing to a 67,108,872-byte signed envelope with a 64 MiB payload and a one-byte signature.\n2. `Hex.Repo.get_package(\"hexpm\", \"probe\", nil)`, which calls the vendored `hex_repo:get_package/2`, returns `{:error, :bad_signature}` after allocating the envelope. Peak RSS was 234 MiB, against 96 MiB for a 1,030-byte invalid envelope.\n3. Answer an API request with `content-type: application/vnd.hex+erlang` and 8,178 bytes of compressed Erlang term format encoding a list of 4,194,304 elements. `mix_hex_api:get/2` accepts the decoded term, and BEAM memory rises from 58 MiB to 272 MiB."
}
],
"value": "* Point a repository at a loopback mirror (in Hex, HEX_MIRROR_URL) that answers /packages/probe with a 65,268-byte gzip stream decompressing to a 67,108,872-byte signed envelope with a 64 MiB payload and a one-byte signature.\n* Hex.Repo.get_package(\"hexpm\", \"probe\", nil), which calls the vendored hex_repo:get_package/2, returns {:error, :bad_signature} after allocating the envelope. Peak RSS was 234 MiB, against 96 MiB for a 1,030-byte invalid envelope.\n* Answer an API request with content-type: application/vnd.hex+erlang and 8,178 bytes of compressed Erlang term format encoding a list of 4,194,304 elements. mix_hex_api:get/2 accepts the decoded term, and BEAM memory rises from 58 MiB to 272 MiB."
}
],
"x_technicalAnalysis": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003col\u003e\n\u003cli\u003e\u003ccode\u003ehex_repo:get_protobuf/3\u003c/code\u003e, used by \u003ccode\u003eget_names/1\u003c/code\u003e, \u003ccode\u003eget_versions/1\u003c/code\u003e, \u003ccode\u003eget_package/2\u003c/code\u003e and \u003ccode\u003eget_policy/2\u003c/code\u003e, calls \u003ccode\u003ezlib:gunzip/1\u003c/code\u003e on the whole response body with no output limit.\u003c/li\u003e\n\u003cli\u003e\u003ccode\u003ehex_repo:decode/4\u003c/code\u003e then calls \u003ccode\u003ehex_registry:decode_and_verify_signed/2\u003c/code\u003e, which decodes the protobuf envelope, copying its payload and signature, before checking the signature.\u003c/li\u003e\n\u003cli\u003e\u003ccode\u003ehex_api:request/4\u003c/code\u003e passes every response whose content type contains \u003ccode\u003eapplication/vnd.hex+erlang\u003c/code\u003e to \u003ccode\u003ehex_safe_binary_to_term:safe_binary_to_term/1\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003e\u003ccode\u003esafe_binary_to_term/1\u003c/code\u003e calls \u003ccode\u003ebinary_to_term(Binary, [safe])\u003c/code\u003e, which decompresses compressed terms and builds the whole term, and only then walks it to reject functions and ports.\u003c/li\u003e\n\u003c/ol\u003e"
},
{
"base64": false,
"type": "text/markdown",
"value": "1. `hex_repo:get_protobuf/3`, used by `get_names/1`, `get_versions/1`, `get_package/2` and `get_policy/2`, calls `zlib:gunzip/1` on the whole response body with no output limit.\n2. `hex_repo:decode/4` then calls `hex_registry:decode_and_verify_signed/2`, which decodes the protobuf envelope, copying its payload and signature, before checking the signature.\n3. `hex_api:request/4` passes every response whose content type contains `application/vnd.hex+erlang` to `hex_safe_binary_to_term:safe_binary_to_term/1`.\n4. `safe_binary_to_term/1` calls `binary_to_term(Binary, [safe])`, which decompresses compressed terms and builds the whole term, and only then walks it to reject functions and ports."
}
],
"value": "* hex_repo:get_protobuf/3, used by get_names/1, get_versions/1, get_package/2 and get_policy/2, calls zlib:gunzip/1 on the whole response body with no output limit.\n* hex_repo:decode/4 then calls hex_registry:decode_and_verify_signed/2, which decodes the protobuf envelope, copying its payload and signature, before checking the signature.\n* hex_api:request/4 passes every response whose content type contains application/vnd.hex+erlang to hex_safe_binary_to_term:safe_binary_to_term/1.\n* safe_binary_to_term/1 calls binary_to_term(Binary, [safe]), which decompresses compressed terms and builds the whole term, and only then walks it to reject functions and ports."
}
]
}
},
"cveMetadata": {
"assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"assignerShortName": "EEF",
"cveId": "CVE-2026-105274",
"datePublished": "2026-10-12T16:43:58.730Z",
"dateReserved": "2026-10-10T13:00:02.355Z",
"dateUpdated": "2026-10-12T18:16:57.155Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-105274",
"date": "2026-10-13",
"epss": "0.00422",
"percentile": "0.34747"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"cpes": [
"cpe:2.3:a:erlang:rebar3:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"r3_hex_repo",
"r3_hex_api"
],
"packageName": "rebar3",
"packageURL": "pkg:otp/rebar3?repository_url=https:%2F%2Fgithub.com%2Ferlang%2Frebar3\u0026vcs_url=repository_url=git%2Bhttps:%2F%2Fgithub.com%2Ferlang%2Frebar3.git",
"product": "rebar3",
"programFiles": [
"apps/rebar/src/vendored/r3_hex_repo.erl",
"apps/rebar/src/vendored/r3_hex_api.erl"
],
"programRoutines": [
{
"name": "r3_hex_repo:get_names/1"
},
{
"name": "r3_hex_repo:get_versions/1"
},
{
"name": "r3_hex_repo:get_package/2"
},
{
"name": "r3_hex_api:request/4"
}
],
"repo": "https://github.com/erlang/rebar3",
"vendor": "erlang",
"versions": [
{
"lessThan": "3.27.3",
"status": "affected",
"version": "3.9.1",
"versionType": "semver"
}
]
},
{
"collectionURL": "https://github.com",
"cpes": [
"cpe:2.3:a:erlang:rebar3:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"r3_hex_repo",
"r3_hex_api"
],
"packageName": "erlang/rebar3",
"packageURL": "pkg:github/erlang/rebar3",
"product": "rebar3",
"programFiles": [
"apps/rebar/src/vendored/r3_hex_repo.erl",
"apps/rebar/src/vendored/r3_hex_api.erl"
],
"programRoutines": [
{
"name": "r3_hex_repo:get_names/1"
},
{
"name": "r3_hex_repo:get_versions/1"
},
{
"name": "r3_hex_repo:get_package/2"
},
{
"name": "r3_hex_api:request/4"
}
],
"repo": "https://github.com/erlang/rebar3",
"vendor": "erlang",
"versions": [
{
"lessThan": "360838a22f5b3a88c0358207f2923059bcbb3afb",
"status": "affected",
"version": "209c02ec57c2cc3207ee0174c3af3675b8dc8f79",
"versionType": "git"
}
]
},
{
"collectionURL": "https://repo.hex.pm",
"cpes": [
"cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"hex_repo",
"hex_api",
"hex_safe_binary_to_term"
],
"packageName": "hex_core",
"packageURL": "pkg:hex/hex_core",
"product": "hex_core",
"programFiles": [
"src/hex_repo.erl",
"src/hex_api.erl",
"src/hex_safe_binary_to_term.erl"
],
"programRoutines": [
{
"name": "hex_repo:get_names/1"
},
{
"name": "hex_repo:get_versions/1"
},
{
"name": "hex_repo:get_package/2"
},
{
"name": "hex_repo:get_policy/2"
},
{
"name": "hex_api:request/4"
},
{
"name": "hex_safe_binary_to_term:safe_binary_to_term/1"
}
],
"repo": "https://github.com/hexpm/hex_core",
"vendor": "hexpm",
"versions": [
{
"lessThan": "0.20.0",
"status": "affected",
"version": "0.1.0",
"versionType": "semver"
}
]
},
{
"collectionURL": "https://github.com",
"cpes": [
"cpe:2.3:a:hexpm:hex_core:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"hex_repo",
"hex_api",
"hex_safe_binary_to_term"
],
"packageName": "hexpm/hex_core",
"packageURL": "pkg:github/hexpm/hex_core",
"product": "hex_core",
"programFiles": [
"src/hex_repo.erl",
"src/hex_api.erl",
"src/hex_safe_binary_to_term.erl"
],
"programRoutines": [
{
"name": "hex_repo:get_names/1"
},
{
"name": "hex_repo:get_versions/1"
},
{
"name": "hex_repo:get_package/2"
},
{
"name": "hex_repo:get_policy/2"
},
{
"name": "hex_api:request/4"
},
{
"name": "hex_safe_binary_to_term:safe_binary_to_term/1"
}
],
"repo": "https://github.com/hexpm/hex_core",
"vendor": "hexpm",
"versions": [
{
"lessThan": "ebe25d110717f6a3addba5232cd4a7dc1c76b628",
"status": "affected",
"version": "fbb6d9de472e5edb8d6fb6b32a91cb266137892e",
"versionType": "git"
}
]
},
{
"cpes": [
"cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"mix_hex_repo",
"mix_hex_api"
],
"packageName": "hex",
"packageURL": "pkg:otp/hex?repository_url=https:%2F%2Fgithub.com%2Fhexpm%2Fhex\u0026vcs_url=repository_url=git%2Bhttps:%2F%2Fgithub.com%2Fhexpm%2Fhex.git",
"product": "hex",
"programFiles": [
"src/mix_hex_repo.erl",
"src/mix_hex_api.erl"
],
"programRoutines": [
{
"name": "mix_hex_repo:get_names/1"
},
{
"name": "mix_hex_repo:get_versions/1"
},
{
"name": "mix_hex_repo:get_package/2"
},
{
"name": "mix_hex_repo:get_policy/2"
},
{
"name": "mix_hex_api:request/4"
}
],
"repo": "https://github.com/hexpm/hex",
"vendor": "hexpm",
"versions": [
{
"lessThan": "2.5.2",
"status": "affected",
"version": "2.1.0",
"versionType": "semver"
}
]
},
{
"collectionURL": "https://github.com",
"cpes": [
"cpe:2.3:a:hexpm:hex:*:*:*:*:*:*:*:*"
],
"defaultStatus": "unaffected",
"modules": [
"mix_hex_repo",
"mix_hex_api"
],
"packageName": "hexpm/hex",
"packageURL": "pkg:github/hexpm/hex",
"product": "hex",
"programFiles": [
"src/mix_hex_repo.erl",
"src/mix_hex_api.erl"
],
"programRoutines": [
{
"name": "mix_hex_repo:get_names/1"
},
{
"name": "mix_hex_repo:get_versions/1"
},
{
"name": "mix_hex_repo:get_package/2"
},
{
"name": "mix_hex_repo:get_policy/2"
},
{
"name": "mix_hex_api:request/4"
}
],
"repo": "https://github.com/hexpm/hex",
"vendor": "hexpm",
"versions": [
{
"lessThan": "d8b60eee97abb119d525306f048969a217d793a5",
"status": "affected",
"version": "671f695ac548ed01f5828c2a739ecaa942b21007",
"versionType": "git"
}
]
}
],
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in hexpm hex_core allows an untrusted repository mirror, or a server answering hex_core\u0027s API requests, to exhaust the memory of the Erlang VM running hex_core. The same code is vendored in Hex (mix_hex_repo, mix_hex_api) and rebar3 (r3_hex_repo, r3_hex_api).\n\nhex_repo:get_names/1, hex_repo:get_versions/1, hex_repo:get_package/2 and hex_repo:get_policy/2 decompress the registry response with zlib:gunzip/1 and decode the signed envelope before verifying its signature. A mirror doesn\u0027t have the repository\u0027s private key, but it chooses the compressed bytes, so a small response decompresses into an envelope of any size before the signature check rejects it.\n\nhex_api decodes responses with the application/vnd.hex+erlang content type through hex_safe_binary_to_term:safe_binary_to_term/1, which calls binary_to_term(Binary, [safe]). The safe option prevents atom creation, but it accepts compressed terms and doesn\u0027t limit the size of the decoded term, and the check that rejects functions and ports runs after the term has been built. The fix for CVE-2026-21619 added the safe option and that check without bounding the decoded size.\n\nThis issue affects rebar3: from 3.9.1 before 3.27.3; hex: from 2.1.0 before 2.5.2; hex_core: from 0.1.0 before 0.20.0."
}
],
"id": "CVE-2026-105274",
"lastModified": "2026-10-13T14:31:20.750",
"metrics": {
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 2.1,
"baseSeverity": "LOW",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "ACTIVE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"version": "4.0",
"vulnAvailabilityImpact": "LOW",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"type": "Secondary"
}
]
},
"published": "2026-10-12T17:17:12.457",
"references": [
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://cna.erlef.org/cves/CVE-2026-105274.html"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/erlang/rebar3/commit/209c02ec57c2cc3207ee0174c3af3675b8dc8f79"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/erlang/rebar3/commit/360838a22f5b3a88c0358207f2923059bcbb3afb"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/hexpm/hex/commit/671f695ac548ed01f5828c2a739ecaa942b21007"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/hexpm/hex/commit/d8b60eee97abb119d525306f048969a217d793a5"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/hexpm/hex_core/commit/ebe25d110717f6a3addba5232cd4a7dc1c76b628"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/hexpm/hex_core/commit/fbb6d9de472e5edb8d6fb6b32a91cb266137892e"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://github.com/hexpm/hex_core/security/advisories/GHSA-7c4r-cgf9-9jmq"
},
{
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"url": "https://osv.dev/vulnerability/EEF-CVE-2026-105274"
}
],
"sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-409"
}
],
"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"current_release_date": "2026-10-13T13:26:45+00:00",
"cve": "CVE-2026-105274",
"id": "CVE-2026-105274",
"initial_release_date": "2026-10-12T16:43:58.730000+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "hex_core: hex: rebar3: hex_core: Denial of Service via uncontrolled decompression of repository responses",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-105274.json",
"version": "3"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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