CVE-2026-1526 Affecting librechat package, versions <0.8.4-r3


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.02% (6th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-LIBRECHAT-16078002
  • published16 Apr 2026
  • disclosed12 Mar 2026

Introduced: 12 Mar 2026

CVE-2026-1526  (opens in a new tab)

How to fix?

Upgrade Chainguard librechat to version 0.8.4-r3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream librechat package and not the librechat package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1