CVE-2025-11934
Improper Validation of Signature Algorithm Used in TLS 1.3 CertificateVerify
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
2.1
Improper Validation of Signature Algorithm Used in TLS 1.3 CertificateVerify
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.
- Record
CVE-2025-11934- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2025-198527
2.1
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.
- Record
EUVD-2025-198527- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-wq2x-6c88-jrh3
2.1
Improper input validation in the TLS 1.3 CertificateVerify signature algorithm negotiation in...
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.
- Record
GHSA-wq2x-6c88-jrh3- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
2.1
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.
- Record
CVE-2025-11934- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSVALPINE-CVE-2025-11934
2.7
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.
- Record
ALPINE-CVE-2025-11934- CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-03
OSV
2.1
Improper Validation of Signature Algorithm Used in TLS 1.3 CertificateVerify
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.
- Record
CVE-2025-11934- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2025-11934
2.7
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.
- Record
DEBIAN-CVE-2025-11934- CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2025-11934
2.1
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.
- Record
UBUNTU-CVE-2025-11934- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N - CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
wolfsslAlpine:v3.23 |
5.8.2 up to 5.9.1-r0 | 5.9.1-r0 |
wolfsslAlpine:v3.24 |
5.8.2 up to 5.8.4-r0 | 5.8.4-r0 |
wolfsslDebian:12 |
All versions, plus listed versions 5.5.4-25.5.4-2+deb12u15.5.4-2+deb12u25.5.4-2+deb12u35.5.4-2.1 Show 24 moreShow less5.6.4-15.6.4-25.6.6-15.6.6-1.15.6.6-1.25.6.6-1.35.6.6-1.3~exp15.7.0-0.15.7.0-0.25.7.0-0.35.7.2-0.15.7.2-0.25.7.2-0.35.7.2-0.45.8.2-15.8.2-1.15.8.2-1.25.8.4-15.9.0-0.15.9.0-0.25.9.1-0.15.9.2-15.9.2-1.15.9.2-1.2 |
None known |
wolfsslDebian:13 |
All versions, plus listed versions 5.7.2-0.15.7.2-0.1+deb13u15.7.2-0.1+deb13u25.7.2-0.25.7.2-0.3 Show 11 moreShow less5.7.2-0.45.8.2-15.8.2-1.15.8.2-1.25.8.4-15.9.0-0.15.9.0-0.25.9.1-0.15.9.2-15.9.2-1.15.9.2-1.2 |
None known |
wolfsslUbuntu:16.04:LTS |
All versions, plus listed versions 3.4.8+dfsg-1 |
None known |
wolfsslUbuntu:18.04:LTS |
All versions, plus listed versions 3.10.2+dfsg-23.12.0+dfsg-13.12.2+dfsg-13.13.0+dfsg-1 |
None known |
wolfsslUbuntu:20.04:LTS |
All versions, plus listed versions 4.1.0+dfsg-24.2.0+dfsg-14.2.0+dfsg-24.2.0+dfsg-34.3.0+dfsg-2 |
None known |
wolfsslUbuntu:22.04:LTS |
All versions, plus listed versions 4.6.0-35.0.0-15.1.1-15.2.0-15.2.0-2 |
None known |
wolfsslUbuntu:24.04:LTS |
All versions, plus listed versions 5.5.4-25.5.4-2.15.6.4-25.6.6-1.25.6.6-1.35.6.6-1.3build1 |
None known |
wolfsslUbuntu:25.10 |
All versions, plus listed versions 5.7.2-0.1 |
None known |
wolfsslUbuntu:26.10 |
All versions, plus listed versions 5.9.1-0.15.9.2-1 |
None known |
wolfsslUbuntu:26.04:LTS |
All versions, plus listed versions 5.7.2-0.15.8.2-1.25.8.4-15.9.1-0.1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, facts, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-11934 is a low vulnerability (CVSS 2.1) in Wolfssl, published November 21, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 5th percentile. Fixed in wolfssl 5.9.1-r0.