Connect your agent
AdvisoriesCriticalCheck your lockfilePluginHow it worksPricing Connect your agent

Advisory record · GHSA-rw4j-r22c-9gc3

AsyncSSH: asyncio event-loop freeze via SSH maximum packet size = 0 in SSH_MSG_CHANNEL_OPEN / OPEN_CONFIRMATION

CVSS 6.5 MediumEPSS 0.0039 · 33rd percentile

Published by the GitHub Advisory Database at 17 Sept 2026, 14:53 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
asyncsshPyPI<2.24.02.24.0
Identifiers
GHSA-rw4j-r22c-9gc3 · CVE-2026-62949 · PYSEC-2026-4026
Weakness (CWE)
CWE-835
Tags
Published
17 Sept 2026
Updated
1 Oct 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

AsyncSSH versions before 2.24.0 are vulnerable to an event-loop freeze when a channel maximum packet size of 0 is accepted. A malicious SSH server can trigger this against a client, and an authenticated client can trigger it against a server, which then blocks all connections. Upgrade to AsyncSSH 2.24.0 or later.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
6.5 Medium 3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0039, the 33rd percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:09 UTC First seen by agentprime
  2. 31 Oct 2026, 14:09 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.