CVE-2026-48816 sigstore CVE debrief

Who should care

Defenders responsible for systems and applications using the @sigstore/verify library should assess their exposure and take steps to mitigate potential risks. This includes verifying their usage of the library, reviewing and updating affected systems and dependencies, and monitoring for potential exploitation attempts. Additionally, defenders should prioritize verifying their usage of @sigstore/verify and upgrading to version 3.1.1 or later to mitigate

Why it matters

The vulnerability in @sigstore/verify allows an attacker to influence certificate validity and timestamp verification decisions, requiring defenders to verify their usage and upgrade to version 3.1.1 or later.

• Potential influence on certificate validity and timestamp verification decisions
• Need to verify and upgrade @sigstore/verify to version 3.1.1 or later
• Possible review and update of affected systems and dependencies
• Monitoring for potential exploitation attempts may be necessary

Technical summary

The @sigstore/verify library, used for interacting with Sigstore services, is vulnerable to an issue where an attacker can influence certificate validity and timestamp verification decisions. This occurs because the library derives a transparency-log timestamp from tlogEntries[].integratedTime for bundle v0.2 inclusionProof-only entries, even though the inclusion proof path does not cryptographically bind integratedTime. The issue was fixed in version 3.1.1.

Defensive priority

Defenders should prioritize verifying their usage of @sigstore/verify and upgrading to version 3.1.1 or later to mitigate potential risks.

Recommended defensive actions

• Verify and upgrade @sigstore/verify to version 3.1.1 or later
• Review and update affected systems and dependencies
• Monitor for potential exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, its impact, and the fix. However, additional information on potential exploitation or affected systems is limited. The vulnerability was introduced due to a logical error in the @sigstore/verify library's handling of transparency-log timestamps. The fix in version 3.1.1 addresses this issue by correctly handling timestamps for bundle v0.2 inclusionProof-only entries. Defenders should verify their usage of the library and ensure they are using version 3.1.1 or later to

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.