CVE-2026-6731 json
X.509 name constraint bypass via Subject CN treated as a DNS name
published 2026-06-25 4 mo ago modified 2026-07-25 3 mo ago also EUVD-2026-39555 , GHSA-9c3c-227q-3j67 , JLSEC-2026-755
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 2%
- public exploits
- 0
- none known
Summary
X.509 name constraint bypass via the Subject Common Name when treated as a DNS-type name. A certificate whose Subject CN violates an issuing CA's DNS name constraints could be accepted.
Patch / fix
- julia wolfSSL_jll 5.9.2+0
- wolfssl wolfssl 5.9.2
- wolfssl Debian 12 5.5.4-2+deb12u3
- wolfssl Debian 13 5.7.2-0.1+deb13u2
debian advisories DEBIAN-CVE-2026-6731
- wolfssl Alpine 3.24 5.9.2-r0
alpine advisories ALPINE-CVE-2026-6731
Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- github.com/wolfSSL/wolfssl#10223 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.12% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N |
| CNA | 4.0 | 6.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| OSV | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| julia | wolfSSL_jll | <5.9.2+0 |
5.9.2+0 |
Affected products
- wolfSSL wolfSSL
Classification
- Weakness
-
- CWE-295 Improper Certificate Validation
References
-
github.com
/wolfSSL/wolfssl/pull/10223
patch, issue-tracking, web
-
wolfssl.com
/docs/security-vulnerabilities/
vendor-advisory, web
-
github.com
/advisories/GHSA-9c3c-227q-3j67
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-6731
web
-
wolfssl.com
/docs/security-vulnerabilities
web
Sources
- CVE List CVE-2026-6731
- NVD CVE-2026-6731
- OSV JLSEC-2026-755
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.