Vulnerability-Lookup

GHSA-Q8GF-9RVJ-GMGJ

Vulnerability from github – Published: 2026-08-25 18:12 – Updated: 2026-08-25 18:12

Summary

gRPC Erlang package has unbounded request body accumulation in `read_full_body/3`

Details

Summary

'Elixir.GRPC.Server.Adapters.Cowboy.Handler':read_full_body/3 accumulates every received chunk into a single growing binary with no size cap. When the client omits the grpc-timeout header, the read timeout resolves to :infinity, allowing a slow-trickle attacker to hold the connection open indefinitely while memory grows. A single unauthenticated connection is sufficient to exhaust BEAM memory and crash the node.

Details

The read loop in lib/grpc/server/adapters/cowboy/handler.ex calls :cowboy_req.read_body/2 in a recursive loop, concatenating each chunk: body <> data. There is no running-total check and no configurable maximum body size. As the loop drains the receive buffer, cowboy issues fresh HTTP/2 WINDOW_UPDATE frames, so the client can keep pushing data indefinitely.

The grpc-timeout header is attacker-supplied and optional. When absent, timeout_left_opt(nil) returns :infinity, so the per-chunk read also has no deadline. The two missing controls compound: a fast client can blast multi-gigabyte payloads directly into memory; a slow client can trickle data forever.

PoC

Start any grpc server exposing a unary RPC (no special configuration required).
Open an HTTP/2 connection and send a POST to any unary RPC path with Content-Type: application/grpc+proto — omit the grpc-timeout header.
Stream a large body (e.g. 1 GiB) in chunks without sending the final END_STREAM flag immediately.
Observe BEAM memory growing proportionally to uploaded data with no server-side cap.

Impact

Affects grpc ≥ 0.3.1. No authentication, no special configuration, and no specific RPC method required, the unbounded read is on the default unary ingress path.

References

Introduction commit: https://github.com/elixir-grpc/grpc/commit/d1abe70a6cad6dac4a3f8235d883d7c896989560
Patch commit: https://github.com/elixir-grpc/grpc/commit/49e18c3ec6bb9afe2f712caad3dbab5c56a68a00

Severity

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Hex",
        "name": "grpc"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.3.1"
            },
            {
              "fixed": "1.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-48854"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-25T18:12:05Z",
    "nvd_published_at": "2026-06-15T23:16:45Z",
    "severity": "HIGH"
  },
  "details": "### Summary\n\n`\u0027Elixir.GRPC.Server.Adapters.Cowboy.Handler\u0027:read_full_body/3` accumulates every received chunk into a single growing binary with no size cap. When the client omits the `grpc-timeout` header, the read timeout resolves to `:infinity`, allowing a slow-trickle attacker to hold the connection open indefinitely while memory grows. A single unauthenticated connection is sufficient to exhaust BEAM memory and crash the node.\n\n### Details\n\nThe read loop in `lib/grpc/server/adapters/cowboy/handler.ex` calls `:cowboy_req.read_body/2` in a recursive loop, concatenating each chunk: `body \u003c\u003e data`. There is no running-total check and no configurable maximum body size. As the loop drains the receive buffer, cowboy issues fresh HTTP/2 `WINDOW_UPDATE` frames, so the client can keep pushing data indefinitely.\n\nThe `grpc-timeout` header is attacker-supplied and optional. When absent, `timeout_left_opt(nil)` returns `:infinity`, so the per-chunk read also has no deadline. The two missing controls compound: a fast client can blast multi-gigabyte payloads directly into memory; a slow client can trickle data forever.\n\n### PoC\n\n1. Start any `grpc` server exposing a unary RPC (no special configuration required).\n2. Open an HTTP/2 connection and send a POST to any unary RPC path with `Content-Type: application/grpc+proto` \u2014 omit the `grpc-timeout` header.\n3. Stream a large body (e.g. 1 GiB) in chunks without sending the final `END_STREAM` flag immediately.\n4. Observe BEAM memory growing proportionally to uploaded data with no server-side cap.\n\n### Impact\n\nAffects `grpc` \u2265 0.3.1. No authentication, no special configuration, and no specific RPC method required, the unbounded read is on the default unary ingress path.\n\n### References\n\n* Introduction commit: https://github.com/elixir-grpc/grpc/commit/d1abe70a6cad6dac4a3f8235d883d7c896989560\n* Patch commit: https://github.com/elixir-grpc/grpc/commit/49e18c3ec6bb9afe2f712caad3dbab5c56a68a00",
  "id": "GHSA-q8gf-9rvj-gmgj",
  "modified": "2026-08-25T18:12:05Z",
  "published": "2026-08-25T18:12:05Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/elixir-grpc/grpc/security/advisories/GHSA-q8gf-9rvj-gmgj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48854"
    },
    {
      "type": "WEB",
      "url": "https://github.com/elixir-grpc/grpc/pull/542"
    },
    {
      "type": "WEB",
      "url": "https://github.com/elixir-grpc/grpc/commit/49e18c3ec6bb9afe2f712caad3dbab5c56a68a00"
    },
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-48854.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/elixir-grpc/grpc"
    },
    {
      "type": "WEB",
      "url": "https://github.com/elixir-grpc/grpc/releases/tag/v1.0.0"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-48854"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "gRPC Erlang package has unbounded request body accumulation in `read_full_body/3`"
}

CVE-2026-48854 (GCVE-0-2026-48854)

Vulnerability from cvelistv5 – Published: 2026-06-15 21:55 – Updated: 2026-09-24 21:09

Title

Unbounded request body accumulation causes memory exhaustion in elixir-grpc/grpc

Summary

Allocation of Resources Without Limits or Throttling vulnerability in elixir-grpc grpc allows unauthenticated attackers to exhaust the BEAM's memory and crash the server by streaming a large or slow-trickle unary request body. 'Elixir.GRPC.Server.Adapters.Cowboy.Handler':read_full_body/3 (lib/grpc/server/adapters/cowboy/handler.ex) accumulates every received chunk into a single growing binary with no size cap. Additionally, when the client omits the grpc-timeout header, the per-chunk read timeout resolves to :infinity, allowing a slow-trickle client to keep the connection alive indefinitely while memory grows. A single connection is sufficient to exhaust server memory and crash the node. This issue affects grpc: from 0.3.0-alpha.2 before 1.0.0.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-16 14:47 UTC

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

EEF CNA under the mitre root

CNA scorecard A 97/100 over 352 records in the last 180 days details

References

5 references

URL	Tags
https://github.com/elixir-grpc/grpc/security/advi…	vendor-advisoryrelated
https://cna.erlef.org/cves/CVE-2026-48854.html	related
https://osv.dev/vulnerability/EEF-CVE-2026-48854	related
https://github.com/elixir-grpc/grpc/commit/d1abe7…	related
https://github.com/elixir-grpc/grpc/commit/49e18c…	patch

Impacted products

2 products

Vendor	Product	Version
elixir-grpc	grpc	Affected: 0.3.0-alpha.2 , < 1.0.0 (semver) cpe:2.3:a:elixir-grpc:grpc::::::::
elixir-grpc	grpc	Affected: d1abe70a6cad6dac4a3f8235d883d7c896989560 , < 49e18c3ec6bb9afe2f712caad3dbab5c56a68a00 (git) cpe:2.3:a:elixir-grpc:grpc::::::::

Date Public

2026-06-15 21:55

Credits

Peter Ullrich Paulo Valente Jonatan Männchen / EEF

Show details on NVD website

JSON

To clipboard

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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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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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.

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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GHSA-Q8GF-9RVJ-GMGJ

Summary

Details

PoC

Impact

References

CVE-2026-48854 (GCVE-0-2026-48854)

Tags

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Nomenclature

Vulnerability timeline

Related by attack behaviour