#VU123426 Heap-based buffer overflow in Vim - CVE-2026-28420
Published: March 3, 2026
Vulnerability identifier: #VU123426
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-28420
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Vim
Vim
Software vendor:
Vim.org
Vim.org
Description
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error within the handle_pushline() function in src/terminal.c processing maximum combining characters from Unicode supplementary planes. A remote attacker can trick the victim into copying a specially crafted string into the :terminal buffer, trigger a heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Remediation
Install updates from vendor's website.