CVE-2026-75883

Name	CVE-2026-75883
Description	The code in pppd that formats a response to a PEAP Request packet in peap_response() copies an entire TLS record of up to 16384 bytes into the fixed global buffer outpacket_buf without checking the available space and without implementing outgoing PEAP fragmentation. Thus a pppd process connecting to a server which requests PEAP authentication can be induced to corrupt global static data following the outpacket_buf array, most likely causing incorrect behavior or a crash.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-4808-1
Debian Bugs	1148816

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
network-manager-l2tp (PTS)	bookworm	1.20.8-1	vulnerable
	bookworm (security)	1.20.8-1+deb12u1	fixed
ppp (PTS)	bookworm	2.4.9-1+1.1	fixed
	trixie	2.5.2-1+1	vulnerable
	forky, sid	2.5.2-1+2	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin	Debian Bugs
network-manager-l2tp	source	bookworm	1.20.8-1+deb12u1	DLA-4808-1
ppp	source	bookworm	(not affected)
ppp	source	(unstable)	(unfixed)		1148816

[bookworm] - ppp <not-affected> (PEAP support introduced in 2.5.0)
https://github.com/ppp-project/ppp/security/advisories/GHSA-rwr9-4vx8-vc35