Vulnerability · Published Oct 27, 2026 · Assigned by GitHub_M

CVE-2026-116775pageant: unbounded frame buffering on peer-controlled 4-byte length prefix (memory-exhaustion DoS)

Low 2.3

In plain English

A low-severity resource allocation without limits in russh from Eugeny. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 4.0)2.3Low

Exploit odds (30 days)0.3%top 77.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

pageant provides a PageantStream type that implements AsyncRead and AsyncWrite traits and can be used to communicate with a running Pageant instance. From 0.2.0 until 0.2.5, PageantStream::new in pageant/src/wmmessage.rs trusts a peer-controlled four-byte length prefix and buffers until len + 4 bytes are available without checking the fixed _AGENT_MAX_MSGLEN transport capacity. An application that bridges an SSH forwarded-agent channel to the raw stream can allow a malicious server to force large allocations or retain a partially filled frame, causing client memory exhaustion. This issue is fixed in version 0.2.5.

Affected products (as reported)

Vendor	Product	Versions
Eugeny	russh	>= 0.2.0, < 0.2.5

Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

https://github.com/Eugeny/russh/security/advisories/GHSA-662x-8wvj-2276 x_refsource_CONFIRM
https://github.com/Eugeny/russh/commit/69e4b55513eaa8ac9d2ad4236f13171fc164e10a x_refsource_MISC
https://github.com/Eugeny/russh/releases/tag/v0.65.0 x_refsource_MISC