CVE-2026-57455: Vim stack out-of-bounds write in spell_soundfold_sofo

CVE-2026-57455 · Severity: info · CVSS 5.4 · Published 2026-06-25

Vim is a widely used open-source text editor. A vulnerability in its spell-checking component allows the application to crash or potentially execute unauthorized code when processing specially crafted, long words. This occurs when the editor is configured with specific language settings and 8-bit encodings, potentially leading to a loss of availability or a compromise of the user's session if they interact with malicious input.

Technologies: Vim. Vendors: Vim.

Quick answers

Is CVE-2026-57455 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-57455 being exploited in the wild.
How severe is CVE-2026-57455?
Informational severity, with a CVSS score of 5.4, published 25 June 2026.
Which products and versions are affected?
Vim < 9.2.0698.
Is there a fix for CVE-2026-57455?
A patch was published on 2026-06-21: Fixed in patch 9.2.0698 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-57455 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-57455?
Check whether you run Vim at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A stack-based out-of-bounds write exists in the single-byte branch of spell_soundfold_sofo() in src/spell.c. The vulnerability is caused by a copy loop that lacks an upper-bound check against the MAXWLEN-element stack buffer, terminating only on a NUL byte. An attacker can trigger this by providing a word longer than 253 bytes to the soundfold() function or via sound-based spell suggestions while a SOFO-based spell language and a non-multibyte encoding (e.g., latin1) are active. This results in stack corruption and a process crash. The issue is fixed in version 9.2.0698 by adding an abort condition to the loop to validate buffer size.

Affected products

  • Vim Vim < 9.2.0698

Timeline

  • 2026-06-21: disclosed: Vulnerability reported and analyzed by Cipher/Causal Security
  • 2026-06-21: patched: Fixed in patch 9.2.0698
  • 2026-06-25: advisory: NVD and GitHub advisories published

References

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