High

Vim modeline sandbox bypass leading to arbitrary OS command execution

IdentifiersCVE-2026-34982CWE-78· Improper Neutralization of Special…

CVE-2026-34982 is a high-severity vulnerability in Vim affecting versions prior to 9.2.0276. The flaw is a modeline sandbox bypass that can lead to arbitrary operating system command execution when a user opens a specially crafted file. The root cause is that the complete, guitabtooltip, and printheader options are missing the P_MLE modeline protection flag, allowing them to be set through a modeline in ways that bypass intended sandbox restrictions. In addition, the complete option lacks the protections expected for callback-style functionality and can accept attacker-controlled expressions, while the mapset() function does not perform a check_secure() validation, allowing abuse from sandboxed expressions. Together, these weaknesses allow malicious content embedded in a file to escape Vim's modeline security boundaries and trigger command execution in the context of the user running the editor.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows arbitrary OS command execution with the privileges of the user running Vim. This can result in compromise of the local workstation or development environment, including unauthorized access to user data, modification of files, execution of follow-on payloads, and establishment of persistence available to that user context. Because exploitation occurs when a crafted file is opened, the vulnerability is particularly dangerous in developer and administrative workflows where Vim is used to inspect untrusted text or source files.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, disable modeline processing in Vim to prevent untrusted files from setting editor options through modelines. Restrict opening untrusted files in affected Vim versions, especially in workflows that routinely inspect externally supplied source code or text files. Using a patched version remains the preferred mitigation.

Remediation

Patch, then assume compromise.

Upgrade Vim to version 9.2.0276 or later. The fix adds the missing modeline-related security flags to the affected options and enforces proper secure-context validation for the vulnerable functionality, including the missing secure check in mapset(). Apply vendor-supplied updates in downstream packages and distributions that embed or ship affected Vim versions.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

Rocky LinuxRocky Linuxoperating_system

VimVimapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

12 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

12 SOURCESView more in app

cyber security newsNews

Apr 2, 2026

Vim Modeline Bypass Vulnerability Let Attackers Execute Arbitrary OS Commands

A high-severity OS command injection vulnerability in Vim caused by a modeline sandbox bypass, allowing arbitrary command execution when a user opens a specially crafted file.

What this page doesn’t show

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity7