CVE-2026-24137 | sigstore legacy TUF client allows for arbitrary file writes with target cache path traversal

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.

Published: 2026-01-23 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-24137 is rated Low Risk (23.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-24137

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-01-23 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-24137

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.3 4.0 [email protected]

Weakness enumeration for CVE-2026-24137

GitHub Security Advisory for CVE-2026-24137

GHSA-fcv2-xgw5-pqxf · Severity: medium · Ecosystem: go — sigstore legacy TUF client allows for arbitrary file writes with target cache path traversal

OS Trackers for CVE-2026-24137

vendor priority summary link
debian not yet assigned CVE-2026-24137 not yet assigned priority: Debian including 1 source packages (golang-github-sigstore-sigstore), 3 status rows across 3 suites (forky, sid, trixie): resolved 2, open 1. https://security-tracker.debian.org/tracker/CVE-2026-24137
redhat medium — https://access.redhat.com/security/cve/CVE-2026-24137
suse medium CVE-2026-24137 severity moderate: SUSE including 14 source package names (cosign-3.0.5-1.1, cosign-3.0.5-150400.3.35.1, …), 49 product×package rows across 38 product lines (Image SL-Micro, Image SL-Micro-Azure, … (38 product lines)): Fixed 48, First Fixed 1. https://www.suse.com/security/cve/CVE-2026-24137/
ubuntu medium CVE-2026-24137 medium priority: Ubuntu including 1 source packages (golang-github-sigstore-sigstore), 4 status rows across 4 suites (jammy, noble, questing, upstream): needs-triage 3, DNE 1. https://ubuntu.com/security/CVE-2026-24137

Affected software / configurations for CVE-2026-24137

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-24137

cvelogic Threat Intelligence