Stack-based buffer overflow in Vim - CVE-2026-26269

Detailed vulnerability 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 special_keys() function in src/netbeans.c. A remote attacker can trick the victim into opening a specially crafted file that initiates connection with attacker-controlled NetBeans server, trigger a stack-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

How to mitigate CVE-2026-26269

Sources

• https://github.com/vim/vim/security/advisories/GHSA-9w5c-hwr9-hc68
• https://github.com/vim/vim/commit/c5f312aad8e4179e437f81ad39a860cd0ef11970