Cyber Resilience

CVE-2026-52859

Medium

Published: 11 June 2026

Published
11 June 2026
Modified
17 June 2026
KEV Added
Patch
CVSS Score v4 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0030 22.0th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-52859 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Vim Vim. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 22.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

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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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Out-of-bounds read in terminal rendering leads directly to application crash (DoS) when untrusted output is displayed in :terminal.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Affected Assets

vim
vim
≤ 9.2.0565

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References