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Fencer Intel
medium 5.3

CVE-2025-11936 json

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

published 11mo ago modified 23d ago also EUVD-2025-198524

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

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.

Patch / fix

  • wolfssl wolfssl 5.8.4
  • wolfssl Alpine 3.23 5.9.1-r0
  • wolfssl Alpine 3.24 5.8.4-r0

alpine advisories ALPINE-CVE-2025-11936

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
11mo ago

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/wolfSSL/wolfssl/pull/9117 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.3 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
CNA 4.0 6.3 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/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
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected products

  • wolfSSL wolfSSL

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.