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

CVE-2026-39832

CRITICAL 9.1

At a glance

Source: NVD
EPSS: EPSS 0.68 % · percentile 53 (2026-10-31)
State: PUBLISHED
Published: 2026-05-22 02:31 UTC
Updated: 2026-09-15 12:04 UTC
Assigner: Go
NVD status: Modified

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Description

When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.

Weaknesses (CWE)

CWE-281 — Improper Preservation of Permissions
CWE-502 — Deserialization of Untrusted Data

References

Scores

Version	Score	Vector	Scored by
CVSS 3.1	CRITICAL 9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	CISA-ADP
CVSS 3.1	HIGH 8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N	redhat-SADP
CVSS 3.1	CRITICAL 9.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)
CVSS 3.1	HIGH 8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N	NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary)

Advisories

GHSA-f5wc-c3c7-36mc — golang.org/x/crypto doesn't drop invoking agent constraints when forwarding keys
GO-2026-5006 — Invoking agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent

European references

ENISA EUVD · EUVD-2026-31390
GCVE · GCVE-0-2026-39832

CERT-FR advisories

CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
CERTFR-2026-AVI-1366 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
CERTFR-2026-AVI-1281 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
CERTFR-2026-AVI-1249 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
CERTFR-2026-AVI-0958 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
CERTFR-2026-AVI-0901 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:* < 0.52.0

Affected products

Product	Versions
golang.org/x/crypto · golang.org/x/crypto/ssh/agent	affected 0 < 0.52.0

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD

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