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19Track

Vim: Out-of-bounds Read in Terminal Screen Snapshot

vim · CVE-2026-52859
0 news outlets0 CERTs and agencies0 researchers

Assessment: Track

SSVC decision points: exploitation none, automatable yes, technical impact partial, deployment low.

What is it?

Vim is an open source, command line text editor. Prior to version 9.2.0565, the update_snapshot() function in src/terminal.c copies the visible terminal screen into the scrollback buffer when a snapshot is taken. For each screen cell it walks the cell's chars[] array with no upper bound, stopping only when it encounters a NUL terminator. When a cell legitimately fills all VTERM_MAX_CHARS_PER_CELL (6) slots — a base character plus five combining marks — the bundled libvterm returns the array without a terminating NUL, so the loop reads past the fixed six-element array and appends the out-of-bounds values to a buffer reserved for only six characters. A program whose output is rendered inside a :terminal window can trigger this with a short byte sequence and no Vim scripting, leading to a crash. This issue has been patched in version 9.2.0565.

Evidence

No coverage recorded yet.

Exploitation

  • Public proof of concept
  • Exploited in the wild
  • Listed as known exploited
CVSS
6.9
EPSS
0.3%
First seen
7 d ago
Status
corroborated

All vim vulnerabilities