# CVE-2026-6329: wolfSSL improper MAC verification in PKCS#12

Source: https://junglewise.ai/threats/cve-2026-6329-wolfssl-improper-mac-verification-in-pkcs-12  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-25. Updated: 2026-06-25  
License: CC BY 4.0 with a link back

CVE-2026-6329 · Severity: info · CVSS 6 · Published 2026-06-25

wolfSSL is a security library used to protect data and communications in embedded devices and cloud applications. A flaw in how it handles PKCS#12 files (commonly used for storing certificates and keys) allows an attacker to bypass integrity checks by providing a specially crafted file with a shortened or empty security code. This could allow an attacker to modify sensitive cryptographic data without the system detecting the tampering.

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

## Quick answers

**Is CVE-2026-6329 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-6329 being exploited in the wild.

**How severe is CVE-2026-6329?** Informational severity, with a CVSS score of 6, published 25 June 2026.

**Which products and versions are affected?** Wolfssl 3.10.0 to 5.9.1.

**Is there a fix for CVE-2026-6329?** A patch was published on 2026-04-15: Fix merged into wolfSSL master branch via Pull Request 10192 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-6329 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-6329?** 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

A vulnerability exists in wolfSSL's PKCS#12 MAC verification path within 'wolfcrypt/src/pkcs12.c'. The implementation compares the locally computed HMAC against the MAC parsed from the PKCS#12 structure using a length value provided in the attacker-supplied input. Because the library fails to verify that this length matches the expected digest size of the configured algorithm, an attacker can provide a truncated or zero-length MAC that will be accepted as valid. This effectively defeats the integrity protection of the PKCS#12 container. The issue is addressed in wolfSSL version 5.9.1.

## Affected products

- wolfSSL wolfSSL 3.10.0 to 5.9.1

## Timeline

- 2026-04-15: patched: Fix merged into wolfSSL master branch via Pull Request 10192
- 2026-06-25: advisory: NVD and vendor advisory published

## References

- [https://github.com/wolfSSL/wolfssl](https://github.com/wolfSSL/wolfssl)
- [https://github.com/wolfSSL/wolfssl/pull/10192](https://github.com/wolfSSL/wolfssl/pull/10192)
- [https://www.wolfssl.com/docs/security-vulnerabilities/](https://www.wolfssl.com/docs/security-vulnerabilities/)

## 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)