#VU103998 Use-after-free in Vim - CVE-2025-26603

Vulnerability identifier: #VU103998

Vulnerability risk: High

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2025-26603

CWE-ID: CWE-416

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Vim
Client/Desktop applications / Software for system administration

Vendor: Vim.org

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error within the str_to_reg() function in src/register.c. A remote attacker can trick the victim into opening a specially crafted file and execute arbitrary code on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Vim: 9.1.0 - 9.1.1114

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External links
http://github.com/vim/vim/security/advisories/GHSA-63p5-mwg2-787v
http://github.com/vim/vim/commit/c0f0e2380e5954f4a52a131bf6b8

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.