Vulnerability in Theupdateframework Go-Tuf

CVE-2026-23991

go-tuf is a Go implementation of The Update Framework (TUF). Starting in version 2.0.0 and prior to version 2.3.1, if the TUF repository (or any of its mirrors) returns invalid TUF metadata JSON (valid JSON but not well formed TUF metadata), the client will panic during parsing, causing a denial of service. The panic happens before any signature is validated. This means that a compromised repository/mirror/cache can DoS clients without having access to any signing key. Version 2.3.1 fixes the issue. No known workarounds are available.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (46.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-23991: held from 0.005 to 0.006.

EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-23991?
CVE-2026-23991 is a medium-severity vulnerability in Theupdateframework Go-Tuf, classified under Reachable Assertion. CVSS score: 5.9/10. Published 2026-01-22.
How severe is CVE-2026-23991?
Medium severity. CVSS v3 base score is 5.9 out of 10.