CVE-2026-55961 wolfSSL_PKCS7_verify() reports success for degenerate (certs-only) PKCS#7 with no signer
wolfSSL compatibility layer incorrectly verifies degenerate PKCS#7 objects without signers, allowing bypass of signature validation in OpenSSL-compatible builds.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55961?
CVE-2026-55961 is a high-severity vulnerability in Wolfssl Wolfssl, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
wolfSSL_PKCS7_verify() returning success for a degenerate (certs-only) PKCS#7 object that contains no signer. Such an object has empty signerInfos, so the underlying signed-data verification succeeds without authenticating any content. The compatibility-layer verify path now rejects the object when no signer signature has actually been verified, so a PKCS#7 carrying no valid signature is no longer reported as verified. This is enforced regardless of the PKCS7_NOVERIFY flag, which only suppresses signer certificate chain validation and was never intended to waive the requirement that a signature exist. Only affects OpenSSL compatibility builds that call the PKCS7_verify() compatibility API on potentially degenerate PKCS#7 bundles.
Weakness: CWE-347
Which versions are affected by CVE-2026-55961?
It affects 1 product.
Products include Wolfssl Wolfssl.
How do I fix CVE-2026-55961?
Apply the vendor's patch.
Is CVE-2026-55961 being exploited?
There is no known exploitation of CVE-2026-55961 in the wild and no public exploit code.
Other vulnerabilities in Wolfssl Wolfssl
Sources
Also known as DEBIAN-CVE-2026-55961, GHSA-cj56-5c53-9qjf, JLSEC-2026-736, UBUNTU-CVE-2026-55961.