CVE-2026-54787: sigstore-go · Use of a Key Past its Expiration Date
Affects sigstore-goSource CVE Database V5
Not known to be exploited · CVSS 3.1 Low : upgrade to 1.2.1 when convenient.
Data as of 26 Oct 2026, 12:29 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-07-31.
- Patch
- Available – fixed in 1.2.1
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 31 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade sigstore-go to 1.2.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| sigstoresigstore-go | Affected
| Fixed in
|
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.
References
- github.com/sigstore/sigstore-go/security/advisories/GHSA-wqqc-jjcq-vfxm (opens in a new tab)
- github.com/sigstore/sigstore-go/pull/642 (opens in a new tab)
- github.com/sigstore/sigstore-go/commit/4594ab4c779d08be1f4419803a8249188f35ed5f (opens in a new tab)
- github.com/sigstore/sigstore-go/releases/tag/v1.2.1 (opens in a new tab)