CVE-2026-55892 Vim: Out-of-bounds Write in Spell File Prefix Dump
A crafted spell file causes an out-of-bounds write in Vim, leading to crashes or potential code execution when dumping word lists.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-55892?
CVE-2026-55892 is a medium-severity memory corruption vulnerability in Vim Vim, published on 25 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-787
Which versions are affected by CVE-2026-55892?
It affects 1 product.
Products include Vim Vim.
How do I fix CVE-2026-55892?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-55892 being exploited?
There is no known exploitation of CVE-2026-55892 in the wild and no public exploit code.
Other vulnerabilities in Vim Vim
Sources
Also known as ALPINE-CVE-2026-55892, AZL-91113, BELL-CVE-2026-55892, CLSA-2026-1782896527, CLSA-2026-1782896779, CLSA-2026-1782897117 and 7 more.