CVE-2025-11936

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

MEDIUM
5.3
CVSS Score
Published: November 21, 2025 at 10:24 PM UTC
Updated: October 19, 2026 at 01:10 PM UTC
1 product affected across 1 vendorwolfSSL

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.5%
SSVC
PoC

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.

Affected

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

5.8.2 ≤ v < 5.8.43.12.0
Affected range stops below 5.8.4, so it looks safe — our inference, not a vendor statement

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/9117

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
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20

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