CVE-2025-11934

Improper Validation of Signature Algorithm Used in TLS 1.3 CertificateVerify

LOW
2.7
CVSS Score
Published: November 21, 2025 at 10:12 PM UTC
Updated: October 19, 2026 at 01:10 PM UTC
1 product affected across 1 vendorwolfSSL· also runs on 2 platforms

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Severity
LOW2.7
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

Improper input validation in the TLS 1.3 CertificateVerify signature algorithm negotiation in wolfSSL 5.8.2 and earlier on multiple platforms allows for downgrading the signature algorithm used. For example when a client sends ECDSA P521 as the supported signature algorithm the server previously could respond as ECDSA P256 being the accepted signature algorithm and the connection would continue with using ECDSA P256, if the client supports ECDSA P256.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions5.8.2 ≤ v < 5.8.43.12.0
Affected range stops below 5.8.4, so it looks safe — our inference, not a vendor statement
apple-macos (environment) · linux-linux-kernel (environment)

Runs on — not affected

The affected product only carries this flaw when running on these platforms. The platforms themselves are not vulnerable.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Product
Source: cverecord
https://github.com/wolfSSL/wolfssl
Issue TrackingPatch
Source: cverecord
https://github.com/wolfSSL/wolfssl/pull/9113

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20

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