Common Weakness Enumeration
CWE-409
AllowedImproper Handling of Highly Compressed Data (Data Amplification)
Abstraction: Base · Status: Incomplete
The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
296 vulnerabilities reference this CWE, most recent first.
CVE-2026-53659 (GCVE-0-2026-53659)
Vulnerability from cvelistv5 – Published: 2026-09-14 17:29 – Updated: 2026-09-14 19:03
VLAI
EPSS
VEX
Title
http4k: Unbounded gzip decompression in `ServerFilters.GZip` / `RequestFilters.GunZip` allowed memory-exhaustion DoS
Summary
http4k is a functional toolkit for Kotlin HTTP applications. Prior to 4.51.0.0, 5.42.0.0, and 6.49.0.0, ServerFilters.GZip, RequestFilters.GunZip, and the underlying Gzip request-body decompression functions impose no limit on decompressed size. An unauthenticated client can send a small gzip-encoded request body that expands to gigabytes, exhausting the JVM heap and denying service to other clients. The fix uses SizeLimitedInputStream to enforce a default 10 MiB limit, causes ServerFilters.GZip and RequestFilters.GunZip to return 413 Request Entity Too Large, and causes other decompression paths to throw SizeLimitExceededException. This issue is fixed in versions 4.51.0.0, 5.42.0.0, and 6.49.0.0.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-14 19:03 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/http4k/http4k/security/advisor… | x_refsource_CONFIRM |
| https://github.com/http4k/http4k/commit/2618fe08f… | x_refsource_MISC |
| https://github.com/http4k/http4k/commit/9f9e02f8e… | x_refsource_MISC |
| https://github.com/http4k/http4k/releases/tag/6.49.0.0 | x_refsource_MISC |
Impacted products
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CVE-2026-53524 (GCVE-0-2026-53524)
Vulnerability from cvelistv5 – Published: 2026-08-21 22:18 – Updated: 2026-08-24 20:09
VLAI
EPSS
VEX
Title
WeeChat has a Decompression Bomb in Relay WebSocket (DoS)
Summary
WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 4.3.0 through 4.9.0, the WeeChat relay module's WebSocket permessage-deflate decompression function relay_websocket_inflate() has no upper bound on output size. An authenticated relay user can send a small compressed WebSocket frame (~100 bytes) that decompresses to gigabytes, exhausting all server memory and crashing the entire WeeChat process. The api protocol enables permessage-deflate and requires authentication before WebSocket upgrade. Version 4.9.1 patches the issue.
Severity
6.5 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-24 20:09 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/weechat/weechat/security/advis… | x_refsource_CONFIRM |
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CVE-2026-53430 (GCVE-0-2026-53430)
Vulnerability from cvelistv5 – Published: 2026-06-15 21:55 – Updated: 2026-06-17 04:46
VLAI
EPSS
VEX
Title
grpc gzip decompression bomb in GRPC.Compressor.Gzip.decompress/1
Summary
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-grpc grpc (GRPC.Compressor.Gzip, GRPC.Message modules) allows a denial of service via a gzip decompression bomb.
This vulnerability is associated with program files lib/grpc/compressor/gzip.ex, lib/grpc/message.ex and program routines 'Elixir.GRPC.Compressor.Gzip':decompress/1, 'Elixir.GRPC.Message':from_data/2.
'Elixir.GRPC.Compressor.Gzip':decompress/1 calls :zlib.gunzip/1 directly on attacker-controlled bytes with no decompressed-size limit, ratio check, or incremental decoding. Because this module is the registered gzip GRPC.Compressor implementation, it is invoked automatically whenever an incoming gRPC frame carries the grpc-encoding: gzip header. :zlib.gunzip/1 allocates the entire decompressed result as a single binary, so a small highly compressible payload (for example a few kilobytes of zeros, which gzip compresses at roughly 1000:1) expands to multiple gigabytes inside a single call. The max_receive_message_length limit is enforced only against the already-decompressed message, so it provides no protection. An unauthenticated remote peer can send a single crafted frame to exhaust the BEAM node's heap and trigger an out-of-memory kill.
This issue affects grpc: from 0.4.0 before 1.0.0.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-16 14:42 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/elixir-grpc/grpc/security/advi… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-53430.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-53430 | related |
| https://github.com/elixir-grpc/grpc/commit/1afbab… | patch |
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| elixir-grpc | grpc |
Affected:
0.4.0 , < 1.0.0
(semver)
cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:* |
|
| elixir-grpc | grpc |
Affected:
beae6800fc8baf126f3fe7107d86a50e105275ba , < 1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc
(git)
cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:* |
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CVE-2026-49855 (GCVE-0-2026-49855)
Vulnerability from cvelistv5 – Published: 2026-07-14 20:45 – Updated: 2026-07-16 14:56
VLAI
EPSS
VEX
Title
tornado AsyncHTTPClient accumulates decompressed chunks without size limit (gzip bomb)
Summary
Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, Tornado gzip decompression routines processed limited-size chunks but did not enforce an overall limit on accumulated decompressed chunks, allowing a malicious server accessed by SimpleAsyncHTTPClient or an HTTPServer configured with decompress_request=True to consume effectively unlimited memory. This issue is fixed in version 6.5.6.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-16 14:55 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/tornadoweb/tornado/security/ad… | x_refsource_CONFIRM |
| https://github.com/tornadoweb/tornado/pull/3626 | x_refsource_MISC |
| https://github.com/tornadoweb/tornado/commit/ff80… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| tornadoweb | tornado |
Affected:
< 6.5.6
|
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CVE-2026-49755 (GCVE-0-2026-49755)
Vulnerability from cvelistv5 – Published: 2026-06-08 15:20 – Updated: 2026-06-08 17:14
VLAI
EPSS
VEX
Title
Decompression bomb DoS in Req via auto-decoded archive and compressed response bodies
Summary
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in wojtekmach Req allows attacker-controlled HTTP servers to exhaust memory in a Req client via decompression-bomb response bodies.
Req's default response pipeline includes Req.Steps.decode_body/1 and Req.Steps.decompress_body/1 in lib/req/steps.ex. decode_body/1 dispatches on the server-supplied content-type (or URL extension) and calls :zip.extract(body, [:memory]) for application/zip, :erl_tar.extract({:binary, body}, [:memory]) for application/x-tar, and :erl_tar.extract({:binary, body}, [:memory, :compressed]) for application/gzip / .tgz. Each returns the full decompressed archive contents as a [{name, bytes}] list in memory, with no per-entry or total size cap. decompress_body/1 walks the content-encoding header and chains :zlib/:brotli/:ezstd decoders, so a response advertising content-encoding: gzip, gzip, gzip inflates through multiple layers without bound.
Both steps are enabled by default, no caller opt-in is required, and the attacker controls the content-type and content-encoding headers on their own server (or on any host reached via Req's automatic redirect following). A sub-megabyte response can expand to multiple gigabytes on the victim, crashing the BEAM process.
This issue affects req: from 0.1.0 before 0.6.1.
Severity
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-08 16:49 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/wojtekmach/req/security/adviso… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-49755.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-49755 | related |
| https://github.com/wojtekmach/req/commit/84977e5b… | patch |
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| wojtekmach | req |
Affected:
0.1.0 , < 0.6.1
(semver)
cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:* |
|
| wojtekmach | req |
Affected:
e37753741cbdc725e6aba3d977b380163bfc0ecb , < 84977e5b1a83f26e749d55ad06e3625464af4e8d
(git)
cpe:2.3:a:wojtekmach:req:*:*:*:*:*:*:*:* |
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CVE-2026-49158 (GCVE-0-2026-49158)
Vulnerability from cvelistv5 – Published: 2026-07-27 11:05 – Updated: 2026-07-27 13:04
VLAI
EPSS
VEX
Title
Apache Thrift: Ruby THeaderTransport ZLIB Decompression Bomb
Summary
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in Apache Thrift Ruby bindings.
This issue affects Apache Thrift: before 0.24.0.
Users are recommended to upgrade to version 0.24.0, which fixes the issue.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-27 13:04 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://lists.apache.org/thread/7v3jhgwfbmhx42424… | vendor-advisory |
| https://lists.apache.org/thread/fmjl8l415tj9zwlob… | vendor-advisory |
| http://www.openwall.com/lists/oss-security/2026/0… |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Thrift |
Affected:
0 , < 0.24.0
(semver)
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CVE-2026-48594 (GCVE-0-2026-48594)
Vulnerability from cvelistv5 – Published: 2026-06-02 19:08 – Updated: 2026-09-24 20:50
VLAI
EPSS
VEX
Title
Decompression bomb in Tesla.Middleware.DecompressResponse and Tesla.Middleware.Compression
Summary
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-tesla tesla allows a denial of service via decompression bomb in HTTP response bodies.
When Tesla.Middleware.DecompressResponse or Tesla.Middleware.Compression is included in a Tesla middleware pipeline, HTTP response bodies are decompressed eagerly with no size limit. The decompress_body/2 function in lib/tesla/middleware/compression.ex passes the entire response body to :zlib.gunzip/1 or :zlib.unzip/1 without any cap on the output size. Additionally, compression_algorithms/1 splits the content-encoding header on commas and decompress_body/2 recurses once per token, applying a decompression pass on each iteration. A server advertising content-encoding: gzip, gzip, gzip, gzip causes four recursive decompression passes, yielding exponential amplification: each gzip layer can expand its input roughly 1000x, so a payload of a few hundred bytes on the wire inflates to gigabytes of BEAM heap, exhausting memory and crashing or freezing the calling process.
This issue affects tesla: from 0.6.0 before 1.18.3.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-03 14:39 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/elixir-tesla/tesla/security/ad… | vendor-advisoryrelated |
| https://cna.erlef.org/cves/CVE-2026-48594.html | related |
| https://osv.dev/vulnerability/EEF-CVE-2026-48594 | related |
| https://github.com/elixir-tesla/tesla/commit/5bd9… | related |
| https://github.com/elixir-tesla/tesla/commit/340f… | patch |
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| elixir-tesla | tesla |
Affected:
0.6.0 , < 1.18.3
(semver)
cpe:2.3:a:elixir-tesla:tesla:*:*:*:*:*:*:*:* |
|
| elixir-tesla | tesla |
Affected:
5bd90bb5cf0d15e375edc2a66fa322292940fce2 , < 340f75b5d191dc747ef7ac6365bd002d1cd55a9d
(git)
cpe:2.3:a:elixir-tesla:tesla:*:*:*:*:*:*:*:* |
Date Public
2026-06-02 19:08
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CVE-2026-48586 (GCVE-0-2026-48586)
Vulnerability from cvelistv5 – Published: 2026-07-27 11:02 – Updated: 2026-07-27 13:03
VLAI
EPSS
VEX
Title
Apache Thrift, Apache Thrift, Apache Thrift, Apache Thrift, Apache Thrift, Apache Thrift: TZlibTransport Decompression Size Limit
Summary
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in Apache Thrift C++, Java, Python, Go, D, C/GLib bindings.
This issue affects Apache Thrift: before 0.24.0.
Users are recommended to upgrade to version 0.24.0, which fixes the issue.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-27 13:03 UTC
CWE
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://lists.apache.org/thread/7v3jhgwfbmhx42424… | vendor-advisory |
| https://lists.apache.org/thread/p008svsjf9p6bj47w… | vendor-advisory |
| http://www.openwall.com/lists/oss-security/2026/0… |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Apache Software Foundation | Apache Thrift |
Affected:
0 , < 0.24.0
(semver)
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CVE-2026-48510 (GCVE-0-2026-48510)
Vulnerability from cvelistv5 – Published: 2026-06-22 21:16 – Updated: 2026-06-25 15:05
VLAI
EPSS
VEX
Title
MessagePack-CSharp: LZ4 decompression allocates from unbounded declared output lengths
Summary
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, when MessagePack-CSharp decompresses Lz4Block or Lz4BlockArray payloads, it reads declared uncompressed lengths from the wire and allocates output buffers based on those lengths before validating that the compressed data is valid or that the declared expansion is reasonable. A small payload can claim a very large uncompressed length and force a large allocation before LZ4 decoding begins. This vulnerability is fixed in 2.5.301 and 3.1.7.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-23 12:29 UTC
CWE
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/MessagePack-CSharp/MessagePack… | x_refsource_CONFIRM |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| MessagePack-CSharp | MessagePack-CSharp |
Affected:
>= 3.0, < 3.1.7
Affected: < 2.5.301 |
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CVE-2026-48502 (GCVE-0-2026-48502)
Vulnerability from cvelistv5 – Published: 2026-06-22 21:18 – Updated: 2026-06-23 15:05
VLAI
EPSS
VEX
Title
MessagePack-CSharp: Denial of service vulnerabilities can swamp the CPU or crash the process with stack and heap overflows
Summary
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePackReader.ReadDateTime() can allocate stack memory based on an attacker-controlled MessagePack extension length. In the slow path for timestamp extension parsing, the computed tokenSize includes the extension body length from the wire and is used in a stackalloc operation before the extension length is validated as one of the valid timestamp sizes. A very small payload can claim a large timestamp extension body and cause a stack allocation large enough to trigger an uncatchable StackOverflowException, terminating the host process. This vulnerability is fixed in 2.5.301 and 3.1.7.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-23 14:58 UTC
CWE
- CWE-125 - Out-of-bounds Read
- CWE-190 - Integer Overflow or Wraparound
- CWE-407 - Inefficient Algorithmic Complexity
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
- CWE-470 - Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
- CWE-502 - Deserialization of Untrusted Data
- CWE-674 - Uncontrolled Recursion
- CWE-789 - Memory Allocation with Excessive Size Value
- CWE-1188 - Insecure Default Initialization of Resource
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/MessagePack-CSharp/MessagePack… | x_refsource_CONFIRM |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| MessagePack-CSharp | MessagePack-CSharp |
Affected:
>= 3.1.7, < 3.1.7
Affected: < 2.5.301 |
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No mitigation information available for this CWE.
No CAPEC attack patterns related to this CWE.