CVE-2025-11936mediumCWE-20

CVE-2025-11936: medium-severity vulnerability in wolfSSL

Potential DoS Vulnerability through Multiple KeyShareEntry with Same Group in TLS 1.3 ClientHello

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13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 6.3epss 0.5%
In short

A flaw in wolfSSL v5.8.2 allows attackers to crash or slow down a TLS server by sending specially crafted connection requests with duplicate key exchange values, causing the server to waste resources processing them.

Technical detail

The vulnerability stems from improper input validation (CWE-20) in TLS 1.3 KeyShareEntry parsing that fails to detect or reject duplicate entries for identical supported groups in ClientHello messages. An unauthenticated remote attacker can exploit this by sending a crafted ClientHello with multiple KeyShareEntry values referencing the same group, triggering excessive CPU and memory consumption during handshake processing, resulting in denial-of-service.

Summary generated and translated by AI from the official description.
Improper input validation in the TLS 1.3 KeyShareEntry parsing in wolfSSL v5.8.2 on multiple platforms allows a remote unauthenticated attacker to cause a denial-of-service by sending a crafted ClientHello message containing duplicate KeyShareEntry values for the same supported group, leading to excessive CPU and memory consumption during ClientHello processing.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L
Affected products
wolfSSL · wolfSSL
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