Description
A certificate with no dNSName SAN but another SAN type present (e.g. registeredID or iPAddress) bypassed the Subject CN dNSName name-constraint check. The CN-as-DNS fallback was gated on cert->subjectCN != NULL && cert->altNames == NULL && !cert->isCA instead of "no dNSName SAN", so an out-of-scope CN was accepted. This incomplete fix from CVE-2026-6731, leading to the name-constraint check issue, was introduced in wolfSSL version 5.9.2.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| wolfSSL | wolfSSL | 5.9.2 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 13 | wolfssl | No fix yet | — |
| Debian 12 | wolfssl | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | wolfssl | No fix yet | — |
| Ubuntu 26.04 LTS | wolfssl | No fix yet | — |
| Ubuntu 24.04 LTS | wolfssl | No fix yet | — |
| Ubuntu 22.04 LTS | wolfssl | No fix yet | — |
| Ubuntu 20.04 LTS | wolfssl | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | wolfssl | No fix yet | — |
| Ubuntu 16.04 LTS | wolfssl | No fix yet | — |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | wolfssl | 5.9.4-r0 | — |