What’s Vulnerable › Vulnerabilities
CVE-2025-11933: DoS Vulnerability in wolfSSL TLS 1.3 CKS Extension
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-11-21 · updated 2026-10-08
- Weakness: CWE-20
Description
Improper Input Validation in the TLS 1.3 CKS extension parsing in wolfSSL 5.8.2 and earlier on multiple platforms allows a remote unauthenticated attacker to potentially cause a denial-of-service via a crafted ClientHello message with duplicate CKS extensions.
Affected products
- wolfSSL: from 5.8.2 before 5.8.4 — fixed in 5.8.4
How to fix
Upgrade to a fixed version: wolfSSL 5.8.4. Check the vendor advisory for mitigations.
References
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