What is CVE-2026-28421?

CVE-2026-28421 is a medium-severity vulnerability in Vim, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-02-27.

How severe is CVE-2026-28421?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Buffer overflow in Vim

CVE-2026-28421

Vim is an open source, command line text editor. Versions prior to 9.2.0077 have a heap-buffer-overflow and a segmentation fault (SEGV) exist in Vim's swap file recovery logic. Both are caused by unvalidated fields read from crafted pointer blocks within a swap file. Version 9.2.0077 fixes the issue.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.002 (7.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L.

Affected products

Vim — versions < 9.2.0077

Weakness classification (CWE)

References

security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)
security-advisories@github.com (Product, x_refsource_MISC)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2026-28421?: CVE-2026-28421 is a medium-severity vulnerability in Vim, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-02-27.
How severe is CVE-2026-28421?: Medium severity. CVSS v3 base score is 5.3 out of 10.