Vulnerability · Published Jul 31, 2026 · Assigned by GitHub_M
CVE-2026-54787sigstore-go fails to check signature timestamps against a signing key's validity period
Low 3.1
In plain English
A low-severity security flaw in sigstore-go from sigstore. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | sigstore-go | no fix listed | DEBIAN-CVE-2026-54787 |
| Debian:14 | sigstore-go | 1.2.1-1 | DEBIAN-CVE-2026-54787 |
| Go | github.com/sigstore/sigstore-go | 1.2.1 | GHSA-wqqc-jjcq-vfxm |
| Go | github.com/sigstore/sigstore-go | 1.2.1 | GO-2026-6162 |
| Ubuntu:26.10 | sigstore-go | no fix listed | UBUNTU-CVE-2026-54787 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| sigstore | sigstore-go | < 1.2.1 |
Weakness: CWE-324 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
References
- https://github.com/sigstore/sigstore-go/security/advisories/GHSA-wqqc-jjcq-vfxm x_refsource_CONFIRM
- https://github.com/sigstore/sigstore-go/pull/642 x_refsource_MISC
- https://github.com/sigstore/sigstore-go/commit/4594ab4c779d08be1f4419803a8249188f35ed5f x_refsource_MISC
- https://github.com/sigstore/sigstore-go/releases/tag/v1.2.1 x_refsource_MISC