Bug 2499636

Summary: CVE-2026-59857 vim: Vim: Denial of Service via out-of-bounds write in spell sound-folding [fedora-all]
Product: [Fedora] Fedora Reporter: Srikanth Balasubramanian <sbalasub>
Component: vimAssignee: Zdenek Dohnal <zdohnal>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: carlwgeorge, fhrdina, zdohnal
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["ab9afa35-a90a-46a9-bfa7-3007db739416"]}
Fixed In Version: vim-9.2.780-1.fc43, vim-9.2.780-1.fc44, vim-9.2.780-1.fc45 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-07-13 11:42:55 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2498863    

Description Srikanth Balasubramanian 2026-07-13 10:21:50 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Vim is an open source, command line text editor. Prior to 9.2.0725, the single-byte branch of spell_soundfold_sal() in src/spell.c translates a word through a spell file's SAL sound-folding rules into a caller-owned result buffer, but its result writes are guarded with reslen < MAXWLEN, allowing reslen to reach MAXWLEN before res[reslen] = NUL writes one byte past the end of the MAXWLEN-element stack buffer. A boundary-length word passed to soundfold(), or reached via sound-based spell suggestion while a SAL-based spell language is active under a non-multibyte 8-bit encoding, can corrupt the eval_soundfold() stack frame and crash the editor. This issue is fixed in version 9.2.0725.