CVE-2025-62291

EUVD-2026-2870
In the eap-mschapv2 plugin (client-side) in strongSwan before 6.0.3, a malicious EAP-MSCHAPv2 server can send a crafted message of size 6 through 8, and cause an integer underflow that potentially results in a heap-based buffer overflow.
Wrap or Wraparound
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mitreCNA
8.1 HIGH
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
strongswanstrongswan
4.2.12 ≤
𝑥
< 6.0.3
CNA
Debian logo
Debian Releases
Debian Product
Codename
strongswan
bookworm
5.9.8-5+deb12u2
fixed
bookworm (security)
5.9.8-5+deb12u3
fixed
bullseye
vulnerable
bullseye (security)
5.9.1-1+deb11u6
fixed
forky
6.0.5-1
fixed
sid
6.0.5-1
fixed
trixie
6.0.1-6+deb13u2
fixed
trixie (security)
6.0.1-6+deb13u4
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
strongswan
bionic
needs-triage
focal
needs-triage
jammy
Fixed 5.9.5-2ubuntu2.4
released
noble
Fixed 5.9.13-2ubuntu4.24.04.1
released
plucky
Fixed 5.9.13-2ubuntu4.25.04.1
released
questing
Fixed 6.0.1-6ubuntu4.1
released
trusty
needs-triage
xenial
needs-triage
Common Weakness Enumeration
References
https://github.com/strongswan/strongswan/commits/master/src/libcharon/plugins/eap_mschapv2
https://github.com/strongswan/strongswan/releases
https://www.strongswan.org/blog/2025/10/27/strongswan-vulnerability-%28cve-2025-62291%29.html
https://lists.debian.org/debian-lts-announce/2025/11/msg00002.html