CVE-2026-24137

Publication date 23 January 2026

Last updated 23 January 2026


Ubuntu priority

Cvss 3 Severity Score

5.8 · Medium

Score breakdown

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.

Status

Package Ubuntu Release Status
golang-github-sigstore-sigstore 25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy Not in release

Severity score breakdown

Parameter Value
Base score 5.8 · Medium
Attack vector Network
Attack complexity High
Privileges required High
User interaction None
Scope Changed
Confidentiality None
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N