# CVE-2026-88647: CVE-2026-88647

Status: published. Published: 2026-10-08. Updated: 2026-11-04.

GnuTLS v3.8.13 can perhaps unexpectedly trust a certificate on the basis of Common Name when Subject Alternative Name has an SRV otherName (1.3.6.1.5.5.7.8.7) whose value is an OCTET STRING. NOTE: the Supplier does not consider this an actionable security vulnerability because of its "threat model doesn't consider attacks only possible by modifying anything within the trust boundary (private keys, trusted certificate authorities and their issued certificates including intermediate CAs, etc.)" policy.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- n/a / n/a: Version not specified (affected). Source: CNA: mitre

## Severity and prioritization

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N; source: ADP: CISA-ADP

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N; source: NVD: 134c704f-9b21-4f2e-91b3-4a467353bcc0

- CISA KEV: No listing in collected sources

- EPSS: 0.21% as of 2026-11-03; percentile 10.90%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-297

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://gitlab.com/gnutls/gnutls/-/issues/1802 (CNA: mitre)

- https://gist.github.com/lkloliver/f98ec3de1a871fdfc02b70b8b9ba7642 (CNA: mitre)

- https://gitlab.com/gnutls/gnutls/-/work_items/1965 (CNA: mitre)

- https://gitlab.com/gnutls/gnutls/-/blob/e2169a87c7fb91935c2845088204b102baed4c5f/SECURITY.md (CNA: mitre)

- https://github.com/lkloliver/poc/tree/main/CVE-2026-88647 (ADP: CVE)

- https://gist.github.com/lkloliver/f98ec3de1a871fdfc02b70b8b9ba7642 (cve@mitre.org)

- https://gitlab.com/gnutls/gnutls/-/blob/e2169a87c7fb91935c2845088204b102baed4c5f/SECURITY.md (cve@mitre.org)

- https://gitlab.com/gnutls/gnutls/-/issues/1802 (cve@mitre.org)

- https://gitlab.com/gnutls/gnutls/-/work_items/1965 (cve@mitre.org)

- https://github.com/lkloliver/poc/tree/main/CVE-2026-88647 (af854a3a-2127-422b-91ae-364da2661108)

## Provenance

- CNA: mitre: https://www.cve.org/CVERecord?id=CVE-2026-88647; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88647; retrieved 2026-11-04; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-88647; retrieved 2026-11-04; source updated Not reported

Revision: e346962ef7375b9576e25e2cf3baa060f0751a411f93b8dd2b7673ef36222c6c

Canonical: https://y2.dev/cve/CVE-2026-88647

## Agent and API access

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- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.