SB2026061854 - Out-of-bounds write in Vim

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-55892)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to out-of-bounds write in the dump_prefixes() function in src/spell.c when parsing a crafted .spl spell file during word list dumping. A remote attacker can supply a crafted spell file to cause a denial of service.

User interaction is required: spell checking must be enabled and the user must dump the word list, such as via :spelldump or spelling completion.

Remediation

Install update from vendor's website.

References

• https://github.com/vim/vim/security/advisories/GHSA-qm9w-fmpj-879h
• https://github.com/vim/vim/commit/8325b193bba5f01e7a7d8241f