Vim up to 9.1.2147 NetBeans Feature src/netbeans.c special_keys stack-based overflow

Summaryinfo

A vulnerability was found in Vim up to 9.1.2147. It has been classified as critical. The affected element is the function special_keys of the file src/netbeans.c of the component NetBeans Feature. Performing a manipulation results in stack-based overflow. This vulnerability is known as CVE-2026-26269. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, was found in Vim up to 9.1.2147. This affects the function special_keys of the file src/netbeans.c of the component NetBeans Feature. The manipulation with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Vim is an open source, command line text editor. Prior to 9.1.2148, a stack buffer overflow vulnerability exists in Vim's NetBeans integration when processing the specialKeys command, affecting Vim builds that enable and use the NetBeans feature. The Stack buffer overflow exists in special_keys() (in src/netbeans.c). The while (*tok) loop writes two bytes per iteration into a 64-byte stack buffer (keybuf) with no bounds check. A malicious NetBeans server can overflow keybuf with a single specialKeys command. The issue has been fixed as of Vim patch v9.1.2148.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-26269 since 02/12/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 299054 (Linux Distros Unpatched Vulnerability : CVE-2026-26269), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 9.1.2148 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch c5f312aad8e4179e437f81ad39a860cd0ef11970 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (299054) and CERT Bund (WID-SEC-2026-0419). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Fedora Linux
• Ubuntu Linux
• SUSE Linux
• Open Source vim

Productinfo

Type

• Word Processing Software

Name

• Vim

Version

• 9.1.2147

License

• open-source

Website

• Product: https://github.com/vim/vim/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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