CVE-2026-25749
Heap Buffer Overflow in Vim Tag File Resolution (Pre
Publication date: 2026-02-06
Last updated on: 2026-02-20
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| vim | vim | to 9.1.2132 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-122 | A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a heap buffer overflow in the Vim text editor, specifically in the tag file resolution logic when processing the 'helpfile' option.
The issue occurs in the get_tagfname() function in the source code file src/tag.c, where Vim copies the user-controlled 'helpfile' option value into a fixed-size heap buffer without checking if the input fits, using an unsafe STRCPY() operation.
Because the buffer size is fixed (MAXPATHL + 1 bytes, typically 4097 bytes), if the input is larger, it can overflow the buffer, leading to potential memory corruption.
This vulnerability was fixed in Vim version 9.1.2132.
How can this vulnerability impact me? :
The vulnerability can lead to a heap buffer overflow, which may allow an attacker to cause a denial of service or potentially execute arbitrary code with the privileges of the user running Vim.
According to the CVSS v3.1 score, the attack requires local access with low privileges and user interaction, but it can result in high impact on integrity and availability.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade Vim to version 9.1.2132 or later, where the heap buffer overflow issue in the get_tagfname() function has been patched.