CVE-2026-24137: sigstore framework is a common go library shared across sigstore services and clients. In versions 1.10.3 and below, the legacy TUF client (pkg/tuf/cl...

Description

sigstore framework is a common go library shared across sigstore services and clients. In versions 1.10.3 and below, the legacy TUF client (pkg/tuf/client.go) supports caching target files to disk. It constructs a filesystem path by joining a cache base directory with a target name sourced from signed target metadata; however, it does not validate that the resulting path stays within the cache base directory. A malicious TUF repository can trigger arbitrary file overwriting, limited to the permissions that the calling process has. Note that this should only affect clients that are directly using the TUF client in sigstore/sigstore or are using an older version of Cosign. Public Sigstore deployment users are unaffected, as TUF metadata is validated by a quorum of trusted collaborators. This issue has been fixed in version 1.10.4. As a workaround, users can disable disk caching for the legacy client by setting SIGSTORE_NO_CACHE=true in the environment, migrate to https://github.com/sigstore/sigstore-go/tree/main/pkg/tuf, or upgrade to the latest sigstore/sigstore release.

Metrics

CVSS 3.1

5.8/10

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N

EPSS Probability

0.37%

28.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

References

Timeline

Published: Jan 23, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-24137?

sigstore framework is a common go library shared across sigstore services and clients. In versions 1.10.3 and below, the legacy TUF client (pkg/tuf/client.go) supports caching target files to disk. It constructs a filesystem path by joining a cache base directory with a target name sourced from signed target metadata; however, it does not validate that the resulting path stays within the cache base directory. A malicious TUF repository can trigger arbitrary file overwriting, limited to the permissions that the calling process has. Note that this should only affect clients that are directly using the TUF client in sigstore/sigstore or are using an older version of Cosign. Public Sigstore deployment users are unaffected, as TUF metadata is validated by a quorum of trusted collaborators. This issue has been fixed in version 1.10.4. As a workaround, users can disable disk caching for the legacy client by setting SIGSTORE_NO_CACHE=true in the environment, migrate to https://github.com/sigstore/sigstore-go/tree/main/pkg/tuf, or upgrade to the latest sigstore/sigstore release.

How severe is CVE-2026-24137?

CVE-2026-24137 has a CVSS score of 5.8/10 (MEDIUM severity). The EPSS model estimates a 0.37% probability of exploitation in the next 30 days.

How do I fix CVE-2026-24137?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.