CVE-2026-55693

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-25 16:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-26 14:17 UTC Last updatedMost recent change to the record

Details

Published

2026-06-25 16:16 UTC

Last modified

2026-06-26 14:17 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-787 · Out-of-bounds write

Record status

Analyzed

Affected

• Vim < 9.2.0653

Attack profile CVSS 4.0 · 5.7

Attack vector

Local

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

Active

Confidentiality

High

Integrity

High

Availability

High