Out-of-bounds write in PPP - CVE-2026-85495
Published: September 19, 2026
Vulnerability identifier: #VU151456
CSH Severity: Low
CVSS v4: 2.3 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-85495
CWE-ID: CWE-787
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause memory corruption.
The vulnerability exists due to an out-of-bounds write in pppd's lcp_reqci() LCP Configure-NAK construction when processing an LCP Configure-Request containing repeated PAP AUTHTYPE options. A remote attacker can send a crafted pre-authentication Configure-Request to cause memory corruption.
The issue is triggered when pppd is configured to refuse PAP and EAP while requiring CHAP.
Affected software
PPP
How to mitigate CVE-2026-85495
Install security update from vendor's website.
PPP - update to 2.5.4