Buffer overflow in Neovim
CVE-2026-25749
Vim is an open source, command line text editor. Prior to version 9.1.2132, a heap buffer overflow vulnerability exists in Vim's tag file resolution logic when processing the 'helpfile' option. The vulnerability is located in the get_tagfname() function in src/tag.c. When processing help file tags, Vim copies the user-controlled 'helpfile' option value into a fixed-size heap buffer of MAXPATHL + 1 bytes (typically 4097 bytes) using an unsafe STRCPY() operation without any bounds checking. This issue has been patched in version 9.1.2132.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.6 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (8.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 8.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000
Affected products
Weakness classification (CWE)
References
- github.com/vim/vim/security/advisories/GHSA-5w93-4g67-mm43 (Exploit, Patch, Vendor Advisory)
- github.com/vim/vim/commit/0714b15940b245108e6e9d7aa2260dd849a26fa9 (Patch)
- github.com/vim/vim/releases/tag/v9.1.2132 (Product)
Frequently asked questions
- What is CVE-2026-25749?
- CVE-2026-25749 is a medium-severity vulnerability in Neovim, classified under Heap-based Buffer Overflow. CVSS score: 6.6/10. Published 2026-02-06.
- How severe is CVE-2026-25749?
- Medium severity. CVSS v3 base score is 6.6 out of 10.