GHSA-f5wc-c3c7-36mc: golang.org/x/crypto (CVE-2026-39832)

Invoking agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent

CVSS 9.1 CriticalCriticalEPSS 0.0068 · 52nd percentile

Critical, because:

CVSS score 9.1: 9.0 or more.

Published by the GitHub Advisory Database at 22 May 2026, 02:08 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
golang.org/x/crypto	Go	<0.52.0	0.52.0

Identifiers

GHSA-f5wc-c3c7-36mc · CVE-2026-39832 · GO-2026-5006

Weakness (CWE)

CWE-281

Machine-written summary

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

Affected: golang.org/x/crypto versions before 0.52.0. When keys were added to a remote agent, constraint extensions such as [email protected] were not sent, so destination restrictions were silently dropped when forwarding keys. This could let a key be used without its intended limits on the remote host. Upgrade to golang.org/x/crypto 0.52.0 or later, which serializes all constraint extensions and makes the in-memory keyring reject unsupported ones.

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

Score	Rating	CVSS	Vector	Source
9.1	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	ADP (CISA-ADP)

CISA KEV Not listed.
EPSS 0.0068, the 52nd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:13 UTC First seen by agentprime
31 Oct 2026, 14:13 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.