CVE-2026-55693
CVE-2026-55693 is a high-severity vulnerability in Vim with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.
Key facts
- Severity: High (CVSS 3.x base score 7.8)
- CVSS v4: 5.7
- EPSS exploit prediction: 0% (3rd percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-39452
- Weakness: CWE-787
- Affected product: Vim
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-55693?
- 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.
- How severe is CVE-2026-55693?
- CVE-2026-55693 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-55693 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-55693?
- CVE-2026-55693 affects Vim. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-55693?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-55693 have an EU (EUVD) identifier?
- Yes. CVE-2026-55693 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39452.
- When was CVE-2026-55693 published?
- CVE-2026-55693 was published on 2026-06-25 and last updated on 2026-06-26.
References
- https://github.com/vim/vim/commit/a80874d9b84a01040e3d1aef2d4a59e1934dafb7
- https://github.com/vim/vim/releases/tag/v9.2.0653
- https://github.com/vim/vim/security/advisories/GHSA-wgh4-64f7-q3jq
Affected products (1)
- cpe:2.3:a:vim:vim:*:*:*:*:*:*:*:*
More vulnerabilities in Vim
- CVE-2020-20703 — Critical (CVSS 9.8): Buffer Overflow vulnerability in VIM v.8.1.2135 allows a remote attacker to execute arbitrary code via the operand…
- CVE-2022-3520 — Critical (CVSS 9.8): Heap-based Buffer Overflow in GitHub repository vim/vim prior to 9.0.0765.
- CVE-2022-0318 — Critical (CVSS 9.8): Heap-based Buffer Overflow in vim/vim prior to 8.2.
- CVE-2017-6350 — Critical (CVSS 9.8): An integer overflow at an unserialize_uep memory allocation site would occur for vim before patch 8.0.0378, if it does…
- CVE-2017-6349 — Critical (CVSS 9.8): An integer overflow at a u_read_undo memory allocation site would occur for vim before patch 8.0.0377, if it does not…
- CVE-2017-5953 — Critical (CVSS 9.8): vim before patch 8.0.0322 does not properly validate values for tree length when handling a spell file, which may…
Other CWE-787 (Out-of-bounds Write) vulnerabilities
- CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
- CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src modules). This vulnerability is…
- CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
- CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
- CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
- CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…