CVE-2026-55693Vim: Out-of-bounds Write in Spell File Word Count

Description

Vim is an open source, command line text editor. Prior to 9.2.0653, the tree_count_words() function in src/spellfile.c fills in the word-count fields of a spell-file word trie by walking it iteratively with a depth counter. 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 (arridx[], curi[], wordcount[]). A crafted .spl/.sug file pair, loaded when the user invokes spell suggestion, 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 9.2.0653.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://github.com/vim/vim/security/advisories/GHSA-wgh4-64f7-q3jq Vendor Advisory
• https://github.com/vim/vim/commit/a80874d9b84a01040e3d1aef2d4a59e1934dafb7 Patch
• https://github.com/vim/vim/releases/tag/v9.2.0653 Product