CVE-2026-54787

Name	CVE-2026-54787
Description	sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.1, sigstore-go does not check a bundle signing timestamp against the validity window of an ExpiringKey wrapping a self-managed long-lived signing key without a certificate, which can allow an attacker holding expired key material to sign accepted bundles. This issue is fixed in version 1.2.1.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
sigstore-go (PTS)	trixie	0.7.1-2	vulnerable
	forky	1.2.1-1	fixed
	sid	1.2.2-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
sigstore-go	source	(unstable)	1.2.1-1

Notes

https://github.com/sigstore/sigstore-go/security/advisories/GHSA-wqqc-jjcq-vfxm
https://github.com/sigstore/sigstore-go/pull/642
https://github.com/sigstore/sigstore-go/commit/4594ab4c779d08be1f4419803a8249188f35ed5f (v1.2.1)