VulnerabilityPublished 8 Oct 2026Updated 19 Oct 2026

CVE-2026-95210: gnutls · Improper Certificate Validation

Source CVE Database V5

Not known to be exploited · CVSS 4.8 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

4.8Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Until a fix is available, users should consider additional certificate validation measures or avoid using the affected version if possible.

Description

CVE-2026-95210 is a vulnerability in GnuTLS version 3.8.13 where improper certificate validation causes the application to accept certificates containing invalid extensions. This flaw can lead to partial compromise of confidentiality and integrity. The vulnerability has a medium severity rating with a CVSS score of 4.8. No patch or remediation information is currently provided.

Impact

The impact is limited to partial loss of confidentiality and integrity due to acceptance of invalid certificates. This could allow an attacker to bypass some certificate validation checks, potentially enabling man-in-the-middle or spoofing attacks under certain conditions. There is no indication of availability impact. No known exploits are reported in the wild.

Summary

This vulnerability involves improper certificate validation in GnuTLS version 3.8.13. Specifically, the application accepts certificates that contain invalid extensions, which violates proper certificate validation protocols. This can result in an attacker presenting a malformed certificate that is incorrectly accepted by the application, potentially undermining the security guarantees of TLS communications. The CVSS vector indicates a network attack vector with high attack complexity, no privileges required, no user interaction, and impacts confidentiality and integrity but not availability.

CWE-295Improper Certificate Validation (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not validate, or incorrectly validates, a certificate.
Architecture and Design · Implementation
Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
Implementation
If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
OWASP Cheat Sheets
Transport Layer Protection (opens in a new tab)
TLS Cipher String (opens in a new tab)
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V9.2.1 (opens in a new tab)
V1.9.2 (opens in a new tab)
V2.8.5 (opens in a new tab)
Attack patterns
Creating a Rogue Certification Authority Certificate (opens in a new tab)
Signature Spoofing by Improper Validation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 19 Oct 2026, 19:16 UTC

WeaknessesCWE-295

Technical details

References

Community reviews

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