Is CVE-2026-23991 in the CISA KEV catalog?

No. CVE-2026-23991 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-23991?

CVE-2026-23991 has a CVSS v3 base score of 5.9 (MEDIUM).

What is the EPSS score for CVE-2026-23991?

CVE-2026-23991 has an EPSS score of 0.53% (41th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-23991?

Upgrade golang-github-theupdateframework-go-tuf on debian unstable to 2.4.1+0.7.0-1 or later.

CVE & CISA-KEV Catalog

CVE-2026-23991

MEDIUM

5.9

CVSS v3

NVD

Description

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.

CWE-617 CWE-754

How to fix

Remediation Available

golang-github-theupdateframework-go-tufDebian

Fixed in:2.4.1+0.7.0-1CVE-2026-23991

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

0.53%probability of exploitation in 30 days

41stpercentile

Moderate risk: more likely to be exploited than 41% of all known CVEs.

References

Patch1

github.com

Vendor Advisory1

github.com

Release Notes1

github.com

Related Vulnerabilities

Other CWE-617 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-8617	High	7.5	93%	-	Fix
CVE-2020-36222	High	7.5	78%	-	Fix
CVE-2006-5779	High	7.5	75%	-	Fix
CVE-2021-27212	High	7.5	64%	-	Fix
CVE-2018-5740	High	7.5	59%	-	Fix
CVE-2023-28425	Medium	5.5	55%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-17.