CVE-2026-48791: sigstore-java · Improper Verification of Cryptographic Signature
Affects sigstore-javaSource CVE Database V5
Public exploit available · CVSS 2.0 Low.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.07% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- 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, 2026-08-13.
CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 12 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CISA SSVC: proof of concept public
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
Timeline
CVE ID reserved
by GitHub, Inc.
, 82 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 13 hours after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| sigstoresigstore-java | Affected
| Fixed in– |
Description
sigstore-java is a sigstore java client for interacting with sigstore infrastructure. Version 2.0.0 erroneously removed verification of the integrated (Rekor entry) time) against the Fulcio certificate. Version 2.1.0 re-added this verification with enhancements that adhere to the Sigstore verification spec. The old sigstore-conformance test for this check was built incorrectly. This vulnerability impacts only users verifying bundles with `dev.sigstore:sigstore-java:2.0.0`. Older versions are not affected; it is fixed in `dev.sigstore:sigstore-java:2.1.0` A malicious actor may exploit this if they were able to access a users system and exfiltrate the temporary private key used during signing and then reuse an old fulcio certificate later without requiring direct access to the user's credentials. Users may protect themselves by re-verifying their artifacts using the newest sigstore-java or another current sigstore client. Transparency logs may also be audited for unauthorized signatures for a suspected reused identity.
References
- github.com/sigstore/sigstore-java/security/advisories/GHSA-qqw8-7c2r-jxch (opens in a new tab)
- github.com/sigstore/sigstore-java/pull/1008 (opens in a new tab)
- github.com/sigstore/sigstore-java/pull/1185 (opens in a new tab)
- github.com/sigstore/sigstore-java/commit/4b7a49ebb1813f5b1ff113bcad63246358222d61 (opens in a new tab)
- github.com/sigstore/sigstore-java/commit/b529335728fc5cfb574161b4b3c06859a8a2aa88 (opens in a new tab)