PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-34982 vim CVE debrief

CVE-2026-34982 is a high-severity vulnerability in Vim, a popular open-source text editor. The vulnerability allows for arbitrary OS command execution when a user opens a crafted file. This is due to a modeline sandbox bypass issue. Specifically, the `complete`, `guitabtooltip`, and `printheader` options are missing the `P_MLE` flag, allowing a modeline to be executed. Furthermore, the `mapset()` function lacks a `check_secure()` call, making it possible to abuse it from sandboxed expressions. The issue was fixed in Vim version 9.2.0276.

Vendor
vim
Product
Unknown
CVSS
HIGH 8.2
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-06
Original CVE updated
2026-09-18
Advisory published
2026-04-06
Advisory updated
2026-09-18

Who should care

Users of Vim, especially those who work with untrusted files or in environments where file integrity cannot be guaranteed, should be aware of this vulnerability. System administrators and security teams should prioritize patching or mitigating this vulnerability to prevent potential exploitation.

Technical summary

The vulnerability in Vim arises from a modeline sandbox bypass. Vim's modelines are used to set options for a file. However, certain options like `complete`, `guitabtooltip`, and `printheader` were not properly restricted, allowing for arbitrary OS command execution. The `mapset()` function was also vulnerable to abuse. This issue has been addressed in Vim version 9.2.0276 with the addition of the `P_MLE` flag for restricted options and the inclusion of `check_secure()` calls.

Defensive priority

High. This vulnerability allows for arbitrary OS command execution, which can lead to system compromise. Immediate action is recommended to patch or mitigate the vulnerability.

Recommended defensive actions

  • Apply the patch: Update Vim to version 9.2.0276 or later.
  • Restrict access to untrusted files: Ensure that users only have access to files from trusted sources.
  • Implement compensating controls: Use security tools to monitor for suspicious activity related to Vim.
  • Review system logs: Check for any signs of exploitation.
  • Inform users: Educate users about the risks and the importance of patching.

Evidence notes

The CVE record and NVD detail provide comprehensive information about the vulnerability. The source item URL offers additional context from the NVD database. References from GitHub and OpenWall provide further details on the patch and mitigation strategies.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-34982 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-34982

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-34982 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-34982

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.