GHSA-vrm6-8vpv-qv8q

Suggest an improvement
Source
https://github.com/advisories/GHSA-vrm6-8vpv-qv8q
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-vrm6-8vpv-qv8q/GHSA-vrm6-8vpv-qv8q.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-vrm6-8vpv-qv8q
Aliases
Downstream
Related
Published
2026-03-13T20:41:56Z
Modified
2026-03-18T22:58:59.936049Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
Undici has Unbounded Memory Consumption in WebSocket permessage-deflate Decompression
Details

Description

The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompresses incoming compressed frames without enforcing any limit on the decompressed data size. A malicious WebSocket server can send a small compressed frame (a "decompression bomb") that expands to an extremely large size in memory, causing the Node.js process to exhaust available memory and crash or become unresponsive.

The vulnerability exists in the PerMessageDeflate.decompress() method, which accumulates all decompressed chunks in memory and concatenates them into a single Buffer without checking whether the total size exceeds a safe threshold.

Impact

  • Remote denial of service against any Node.js application using undici's WebSocket client
  • A single compressed WebSocket frame of ~6 MB can decompress to ~1 GB or more
  • Memory exhaustion occurs in native/external memory, bypassing V8 heap limits
  • No application-level mitigation is possible as decompression occurs before message delivery

Patches

Users should upgrade to fixed versions.

Workarounds

No workaround are possible.

Database specific
{
    "severity": "HIGH",
    "nvd_published_at": "2026-03-12T21:16:23Z",
    "github_reviewed_at": "2026-03-13T20:41:56Z",
    "cwe_ids": [
        "CWE-409"
    ],
    "github_reviewed": true
}
References

Affected packages

npm / undici

Package

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.24.0

Database specific

source
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-vrm6-8vpv-qv8q/GHSA-vrm6-8vpv-qv8q.json"

npm / undici

Package

Affected ranges

Type
SEMVER
Events
Introduced
7.0.0
Fixed
7.24.0

Database specific

source
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-vrm6-8vpv-qv8q/GHSA-vrm6-8vpv-qv8q.json"