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TI-2026-40366 Aliases CVE-2026-55961GHSA-cj56-5c53-9qjf

wolfSSL_PKCS7_verify() reports success for degenerate (certs-only) PKCS#7 with no signer

Priority LOW 35CWE-347Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-347.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00146 3rd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
wolfSSLwolfSSL3.15.7 – 5.9.1—No fix listedCNA
  • wolfSSL VendorwolfSSL Affected 3.15.7 – 5.9.1 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*3.15.7 to before 5.9.2VulnerablewolfSSL
  • cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:* Versions 3.15.7 to before 5.9.2 Vulnerable ·wolfSSL

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-55961
  2. 2026-10-03 Alias added: GHSA-cj56-5c53-9qjf

References

Patch 1

Advisory 1

  • TI-2024-00830 SEGV and out of bounds memory read from malicious packet CVSS 3.1CRITICAL 9.1
  • TI-2022-18557 In wolfSSL before 5.5.1, malicious clients can cause a buffer overflow during a TLS 1.3… CVSS 3.1HIGH 7.5
  • TI-2025-10943 Potential DoS Vulnerability through Multiple KeyShareEntry with Same Group in TLS 1.3 ClientHello CVSS 4.0MEDIUM 6.3
  • TI-2017-09737 wolfSSL Bleichenbacher/ROBOT CVSS 3.0HIGH 7.5
  • TI-2019-08902 wolfSSL 4.0.0 has a Buffer Overflow in DoPreSharedKeys in tls13.c when a current identity… CVSS 3.1CRITICAL 9.8
  • TI-2017-02021 Improper certificate validation in wolfSSL CVSS 3.1CRITICAL 9.8
See all 150 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences