Vim contains a heap‑based buffer underflow in its Emacs‑style tags file parsing. When a malformed tags file has a delimiter at the beginning of a line, Vim reads memory immediately before the allocated buffer, potentially exposing program memory contents or causing a crash. The flaw is a classic buffer underflow and is classified as CWE‑124 and CWE‑125.

The vulnerability affects all releases of Vim older than version 9.2.0075. Any installation of Vim prior to that patch where it processes Emacs‑style tags files is at risk.

The CVSS score of 5.3 indicates medium severity, and the EPSS score of less than 1 % shows a very low likelihood of exploitation under current conditions. The vulnerability is not listed in the CISA KEV catalog. The most likely attack vector is a local user who can supply or modify a tags file used by Vim, leading to memory disclosure or a denial‑of‑service scenario. While the probability is low, the impact warrants attention.