CVE-2026-48791 Sigstore Java has a vulnerability with bundle verification of integratedTime
Attackers can bypass signature verification by reusing old certificates if the integrated time check is skipped, allowing unauthorized artifact trust.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-48791?
CVE-2026-48791 is a low-severity vulnerability in sigstore-java, published on 12 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-347
Which versions are affected by CVE-2026-48791?
2 open source packages ship an affected version, including dev.sigstore:sigstore-java.
| Package | Affected | Fixed in |
|---|---|---|
dev.sigstore:sigstore-java Maven | From 2.0.0 | 2.1.0 |
dev.sigstore:sigstore-java Maven | From 2.0.0 | 2.1.0 |
How do I fix CVE-2026-48791?
Upgrade dev.sigstore:sigstore-java to 2.1.0 or later.
Is CVE-2026-48791 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48791 exists.
Sources
Also known as GHSA-qqw8-7c2r-jxch, UBUNTU-CVE-2026-48791.