CVE-2026-55892

Name	CVE-2026-55892
Description	Vim is an open source, command line text editor. Prior to 9.2.0662, the dump_prefixes() function in src/spell.c walks a spell-file prefix trie iteratively with a depth counter while dumping the prefixes that apply to a word. The counter is bounded only by the trie structure itself; it is never checked against the size of the fixed MAXWLEN-element stack arrays it indexes (prefix[], arridx[], curi[]). A crafted .spl file, loaded when the user dumps the word list, can drive the descent arbitrarily deep, so the function writes past the end of those arrays. This is a stack out-of-bounds write that corrupts the call frame and crashes the editor. This vulnerability is fixed in 9.2.0662.
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)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
vim (PTS)	bullseye	2:8.2.2434-3+deb11u1	vulnerable
	bullseye (security)	2:8.2.2434-3+deb11u3	vulnerable
	bookworm	2:9.0.1378-2+deb12u2	vulnerable
	trixie	2:9.1.1230-2	vulnerable
	forky, sid	2:9.2.0524-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
vim	source	(unstable)	(unfixed)

Notes

https://github.com/vim/vim/security/advisories/GHSA-qm9w-fmpj-879h
Fixed by: https://github.com/vim/vim/commit/8325b193bba5f01e7a7d8241fc8633d93dff996b (v9.2.0662)