vim up to 9.1.1114 ex_display use after free

Summaryinfo

A vulnerability identified as critical has been detected in vim up to 9.1.1114. Affected by this issue is the function ex_display. The manipulation leads to use after free. This vulnerability is referenced as CVE-2025-26603. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in vim up to 9.1.1114. This issue affects the function ex_display. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Vim is a greatly improved version of the good old UNIX editor Vi. Vim allows to redirect screen messages using the `:redir` ex command to register, variables and files. It also allows to show the contents of registers using the `:registers` or `:display` ex command. When redirecting the output of `:display` to a register, Vim will free the register content before storing the new content in the register. Now when redirecting the `:display` command to a register that is being displayed, Vim will free the content while shortly afterwards trying to access it, which leads to a use-after-free. Vim pre 9.1.1115 checks in the ex_display() function, that it does not try to redirect to a register while displaying this register at the same time. However this check is not complete, and so Vim does not check the `+` and `*` registers (which typically donate the X11/clipboard registers, and when a clipboard connection is not possible will fall back to use register 0 instead. In Patch 9.1.1115 Vim will therefore skip outputting to register zero when trying to redirect to the clipboard registers `*` or `+`. Users are advised to upgrade. There are no known workarounds for this vulnerability.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2025-26603 since 02/12/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful 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 216576 (Fedora 41 : vim (2025-a71acb72e9)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 9.1.1115 eliminates this vulnerability. Applying a patch 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 vulnerability database at Tenable (216576). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Word Processing Software

Name

• vim

Version

• 9.1.1114

License

• open-source

Website

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

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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