# CVE-2026-89102: wolfSSL certificate forgery in OCSP response stapling

Source: https://junglewise.ai/threats/cve-2026-89102-in-wolfssl-versions-5-7-2-through-5-9-2-there-is-a-client-side  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-27. Updated: 2026-09-27  
License: CC BY 4.0 with a link back

CVE-2026-89102 · Severity: info · Published 2026-09-27

wolfSSL is a cryptographic library used to secure communications in embedded systems and applications. A flaw in its OCSP certificate stapling feature allows an attacker with a trusted certificate and its private key to forge certificates for any domain, bypassing the client's certificate validation. This could enable man-in-the-middle attacks and data interception.

Technologies: [Wolfssl](https://junglewise.ai/threats/technologies/wolfssl). Vendors: [Wolfssl](https://junglewise.ai/threats/vendors/wolfssl).

## Quick answers

**Is CVE-2026-89102 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-89102 being exploited in the wild.

**How severe is CVE-2026-89102?** Informational severity, published 27 September 2026.

**Which products and versions are affected?** Wolfssl 5.7.2 through 5.9.2.

**Is there a fix for CVE-2026-89102?** A patch was published on 2026-08-04. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-89102 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-89102?** 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 wolfSSL's RFC 6961 OCSP response stapling implementation when HAVE_CERTIFICATE_STATUS_REQUEST_V2 is enabled and wolfSSL_UseOCSPStaplingV2() is called with WOLFSSL_CSR2_OCSP_MULTI. The client-side flaw fails to verify that peer certificates in the chain are actually authorized to act as CAs, allowing any certificate chaining to a trusted root to be accepted as a CA. Additionally, end-entity certificates are persistently stored in the trust store, affecting subsequent connections even when OCSP multi is not used.

## Affected products

- wolfSSL wolfSSL 5.7.2 through 5.9.2

## Timeline

- 2026-09-27: disclosed
- 2026-08-04: patched

## References

- [https://github.com/wolfSSL/wolfssl/pull/11027](https://github.com/wolfSSL/wolfssl/pull/11027)

## Related threats

- [wolfSSL certificate validation bypass in ConfirmNameConstraints()](https://junglewise.ai/threats/cve-2026-95208-an-issue-in-the-confirmnameconstraints-function-wolfcrypt-src-asn)
- [wolfSSL revocation check bypass with OCSP and CRL](https://junglewise.ai/threats/cve-2026-94417-when-an-application-enables-both-ocsp-and-crl-revocation-checking)
- [wolfSSL TLS 1.2 ChangeCipherSpec message ordering bypass](https://junglewise.ai/threats/cve-2026-93304-a-d-tls-1-2-client-can-accept-a-changecipherspec-message-before)
- [wolfSSL MatchTrustedPeer public key validation bypass](https://junglewise.ai/threats/cve-2026-93302-matchtrustedpeer-ignores-the-public-key-used-leading-to-forged-ca)
- [wolfSSL TLS authentication bypass in Raw Public Key handling](https://junglewise.ai/threats/cve-2026-89136-when-using-rpk-raw-public-key-the-client-side-of-a-tls-1-2-1-3)