Vulnerability · Published Nov 21, 2025 · Assigned by wolfSSL
CVE-2025-11933DoS Vulnerability in wolfSSL TLS 1.3 CKS Extension
Low 2.3
In plain English
A low-severity improper input validation in wolfSSL from wofSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 4.0)2.3Low
Exploit odds (30 days)0.5%top 60.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | wolfssl | 5.9.1-r0 | ALPINE-CVE-2025-11933 |
| Alpine:v3.24 | wolfssl | 5.8.4-r0 | ALPINE-CVE-2025-11933 |
| Debian:12 | wolfssl | no fix listed | DEBIAN-CVE-2025-11933 |
| Debian:13 | wolfssl | no fix listed | DEBIAN-CVE-2025-11933 |
| Ubuntu:22.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2025-11933 |
| Ubuntu:24.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2025-11933 |
| Ubuntu:25.10 | wolfssl | no fix listed | UBUNTU-CVE-2025-11933 |
| Ubuntu:26.04:LTS | wolfssl | no fix listed | UBUNTU-CVE-2025-11933 |
| Ubuntu:26.10 | wolfssl | no fix listed | UBUNTU-CVE-2025-11933 |
Affected products (as reported)
Weakness: CWE-20 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L