WolfsslApplication

CVE-2026-55961

HIGH · 7.5 CVSS v3.1 Published 2026-06-25
Fix available
A fix is available. Upgrade to 5.9.2 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click Patch available 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-347

The application accepts signed data without properly verifying the signature, so an attacker can forge or tamper with content that the system is meant to trust — tokens, updates, licences. Everything built on that trust then becomes unreliable. Remediation is verifying every signature against the correct key and rejecting anything that does not validate.

General guidance for the improper signature verification class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
WolfsslApplication
Affected:>= 3.15.7, < 5.9.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.9.2 or later
Fixed in 5.9.2
Vendor patch github.com →
Recommended fix High confidence

wolfSSL 5.9.2 or later

  1. Identify all systems running wolfSSL versions >= 3.15.7 and < 5.9.2
  2. Determine which affected systems use OpenSSL compatibility builds with the PKCS7_verify() compatibility API
  3. Upgrade wolfSSL to version 5.9.2 or later
  4. Test the upgrade in a non-production environment to verify PKCS#7 signature verification now correctly rejects degenerate (certs-only) PKCS#7 objects
  5. Deploy the patched version to production systems
  6. Verify that existing PKCS#7 verification workflows continue to function correctly with the fix in place
Caveat Applications relying on the previous incorrect behavior (accepting degenerate PKCS#7 with no signer) may now receive expected failure responses; this is the correct security behavior

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-55961 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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