CVE-2026-7531
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 · uneditedUse-after-free in PQC hybrid key-share handling. This is an incomplete-fix follow-up to CVE-2026-5460 (released in 5.9.1): a malicious TLS 1.3 server sending a truncated PQC hybrid KeyShare can still trigger the error cleanup path to operate on freed memory.
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 · moderate confidenceUse-after-free vulnerability in PQC hybrid key-share handling within TLS 1.3. A malicious server sending a truncated Post-Quantum Cryptography hybrid KeyShare can trigger the error cleanup path to operate on already-freed memory, allowing potential memory corruption or code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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>= 5.8.0, < 5.9.2CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify WolfSSL installation and versionRun `wolfssl version` or check your package manager for the installed wolfssl/wolfss package versionAffected if The installed version is 5.8.0, 5.9.0, or 5.9.1 (any version >= 5.8.0 and < 5.9.2)
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Confirm TLS 1.3 support is enabledCheck your WolfSSL compile-time and runtime configuration for TLS 1.3 support using `wolfssl -?` or reviewing your build configuration filesAffected if TLS 1.3 is compiled in or enabled at runtime
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Verify PQC hybrid cipher suites are in useInspect your TLS server/client configuration to determine if Post-Quantum Cryptography hybrid key exchange methods (such as Kyber) are enabled in your cipher suite listAffected if PQC hybrid cipher suites (e.g., TLS 1.3 with hybrid key exchange) are configured or negotiated between clients and servers
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Check for exposure to malicious serversDetermine if your WolfSSL instance acts as a TLS client connecting to external servers, as the vulnerability is triggered by a malicious server sending a truncated hybrid KeyShareAffected if The affected WolfSSL installation is used as a TLS 1.3 client connecting to untrusted or external TLS servers
You are affected if you have WolfSSL versions 5.8.0 through 5.9.1 with TLS 1.3 and PQC hybrid cipher suites enabled, especially when acting as a TLS client connecting to external servers.
Generated from the published advisory. Verify against your own configuration.
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 · scoped5.9.2
Update to the latest version containing the complete fix for this incomplete CVE-2026-5460 patch; if unavailable, consider temporarily disabling PQC hybrid cipher suites in affected TLS implementations until a full patch is released.
WolfSSL 5.9.2 or later
- 1. Identify the current WolfSSL version in use by checking your project dependencies or build system.
- 2. Upgrade WolfSSL to version 5.9.2 or later to address the use-after-free vulnerability in PQC hybrid key-share handling.
- 3. Rebuild and redeploy any applications or services that link against the WolfSSL library.
- 4. Verify the upgrade was successful by checking the new WolfSSL version at runtime.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-7531 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-7531 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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