GnuTLS rejects legitimate CA certificates, causing DoS
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-400.
Summary
GnuTLS v3.8.13 rejects legitimate CA certificates, which causes a denial of service (CWE-400). A remote, unauthenticated attacker may trigger this under high attack complexity, according to the CVSS vector. The issue is disputed because it offers no new denial of service ability, and because enforcing a dNSName constraint against Common Name when Subject Alternative Name is absent can be a reasonable choice.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
An issue in gnutls v3.8.13 causes legitimate CA certificates to be rejected, leading to a Denial of Service (DoS). NOTE: this is disputed by multiple parties because the behavior does not offer a new ability for an adversary to conduct a denial of service, and because the product can reasonably choose to enforce a dNSName constraint against Common Name when Subject Alternative Name is absent.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for gnutls.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 1 product
- Red Hat Hardened Images
Timeline
- 2026-10-09 Threatist record created from CVE-2026-95209
- 2026-10-16 1 new reference · CNA
- 2026-10-16 Alias added: GHSA-8fv7-xp4r-4x4q
- 2026-10-19 CVSS score changed · CISA ADP
- 2026-10-19 CISA SSVC decision points changed
- 2026-10-21 Affected versions changed · Red Hat
- 2026-11-04 1 new reference · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Sources
- CVE-2026-95209 · CVE Program
- CVE-2026-95209 · NVD
- FIRST EPSS
- GHSA-8fv7-xp4r-4x4q · GitHub Advisory Database · CC BY 4.0
- CVE-2026-95209 · Red Hat security data · CC BY 4.0
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