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.

A flaw was found in Vim, an open-source command-line text editor. A remote attacker could exploit this vulnerability by convincing a user to load a specially crafted spell file. This malicious file can trigger a stack out-of-bounds write, which corrupts the editor's memory and causes it to crash. This leads to a Denial of Service (DoS), making the editor unavailable to the user.

A flaw was found in Vim's spell file handling. The dump_prefixes() function in src/spell.c does not validate the depth of the prefix trie against the size of fixed-size stack arrays, allowing a crafted .spl file to cause a stack out-of-bounds write and crash. Red Hat ships Vim in all RHEL versions and OpenShift CoreOS. Exploitation requires a user to load a malicious spell file and run :spelldump or spelling completion. Do not load untrusted spell files (.spl) from unknown sources. Avoid using :spelldump with spell files of unknown provenance. Red Hat Hardened Images 2026-07-03T00:00:00Z RHSA-2026:35387 vim-main-9.2.780-1.hum1 Red Hat Enterprise Linux 10 Fix deferred vim Red Hat Enterprise Linux 6 Fix deferred vim Red Hat Enterprise Linux 7 Fix deferred vim Red Hat Enterprise Linux 8 Fix deferred vim Red Hat Enterprise Linux 9 Fix deferred vim Red Hat OpenShift Container Platform 4 Fix deferred rhcos https://www.cve.org/CVERecord?id=CVE-2026-55892 https://nvd.nist.gov/vuln/detail/CVE-2026-55892 https://github.com/vim/vim/commit/8325b193bba5f01e7a7d8241f https://github.com/vim/vim/releases/tag/v9.2.0662 https://github.com/vim/vim/security/advisories/GHSA-qm9w-fmpj-879h