Quick answers
- Is CVE-2026-89133 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-89133 being exploited in the wild.
- How severe is CVE-2026-89133?
- Informational severity, published 27 September 2026.
- Which products and versions are affected?
- Wolfssl 5.9.2 and earlier.
- Is there a fix for CVE-2026-89133?
- A patch was published on 2026-07-01: Fix merged in PR #10687 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-89133 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-89133?
- 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 is a chain-walking state-machine bug in X.509 certificate validation where NameConstraints extensions are not properly enforced across the entire certificate chain. When an unconstrained CA tier exists between a name-constrained intermediate CA and a leaf certificate, the validation logic incorrectly resets its state, allowing bypasses of cryptographic delegation controls. The flaw affects the default build configuration when name constraint extensions are in use; no authentication or user interaction is required for exploitation.
Affected products
- wolfSSL wolfSSL 5.9.2 and earlier
Timeline
- 2026-09-27: disclosed: Public advisory issued
- 2026-07-01: patched: Fix merged in PR #10687