CVE-2026-88648
Incomplete X.509 implementation in GnuTLS v3.8.13 allows attackers controlling a subordinate Certificate Authority to bypass cross-domain PKI restrictions and issue unauthorized certificates.
02 Description
Incomplete X.509 implementation in GnuTLS v3.8.13 allows attackers controlling a subordinate Certificate Authority to bypass cross-domain PKI restrictions and issue unauthorized certificates.
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.20% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 10.2% of scored records. A rank, not a probability.
- NVD base score
- 3.7 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- NVD analysis status
- Awaiting Analysis. NVD last modified this record on 2026-10-19.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-10-08 00:00Z21 DAYS AGO
- Last updated
- 2026-10-29 12:05Z1 HR AGO
- Reserved
- 2026-09-10
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Low (CVSS 3.7)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- Weaknesses
- CWE-295Improper Certificate ValidationBase
- Data version
- 5.2
- Document digest
- 71d9e69a27987bc0ff65e009e7dbfa9ed391a3d00a13e7953d176968a69b4158
05 Affected products
06 References
- www.rfc-editor.orghttps://www.rfc-editor.org/rfc/rfc5280#section-4.2.1.10
- www.rfc-editor.orghttps://www.rfc-editor.org/rfc/rfc5280#section-6.1.4
- gist.github.comhttps://gist.github.com/lkloliver/1f2a97cb8d0b31aa27b6bd0354358d7d
07 Fixed in
Debian 12
- gnutls28 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- gnutls28 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- gnutls28 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.10
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- gnutls26 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-preview 22.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 22.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 24.04 LTS
- gnutls28 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.