Quick answers
- Is CVE-2026-89134 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-89134 being exploited in the wild.
- How severe is CVE-2026-89134?
- Informational severity, published 27 September 2026.
- Which products and versions are affected?
- Wolfssl 5.9.2 and later (prior to fix).
- Is there a fix for CVE-2026-89134?
- A patch was published on 2026-07-08. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-89134 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-89134?
- Check whether you run Wolfssl at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability exists in the name-constraint validation logic in wolfSSL's certificate chain verification. A certificate lacking a dNSName Subject Alternative Name (SAN) but containing other SAN types (e.g., registeredID or iPAddress) bypasses the CN-as-DNS fallback check due to incomplete logic that only verifies the altNames field is NULL rather than checking for the absence of dNSName SANs. This is a regression from an incomplete fix to CVE-2026-6731 introduced in version 5.9.2, allowing out-of-scope CNs to be accepted when policy constraints should apply.
Affected products
- wolfSSL wolfSSL 5.9.2 and later (prior to fix)
Timeline
- 2026-09-27: disclosed
- 2026-07-08: patched