Bug 2492975 (CVE-2026-55892)

Summary: CVE-2026-55892 vim: Vim: Denial of Service via crafted spell file
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: kshier, rhel-process-autobot, stcannon, teagle, watson-tool-maintainers, yguenane
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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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.
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Description OSIDB Bzimport 2026-06-25 16:02:17 UTC 
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.