CVE-2026-59858 vim CVE debrief

Who should care

Users of Vim version prior to 9.2.0735 who open .c files from untrusted sources should be aware of this vulnerability and take necessary precautions. This includes developers, system administrators, and users who work with .c files. The vulnerability can be exploited by opening a hostile .c file with a crafted tag field and invoking C omni-completion, which can lead to arbitrary Ex command execution.

Technical summary

The C omni-completion script in runtime/autoload/ccomplete.vim interpolates the typeref: or typename: extension field of a tags entry without escaping, into a :vimgrep pattern that is run through :execute. A crafted tag field can close the search pattern and append an arbitrary Ex command, allowing for arbitrary Ex command execution. This vulnerability can be exploited by opening a hostile .c file with a crafted tag field and invoking C omni-completion. The vulnerability is fixed in version 9.2.0735.

Defensive priority

High

Recommended defensive actions

• Update Vim to version 9.2.0735 or later
• Avoid opening .c files from untrusted sources
• Use caution when invoking C omni-completion on untrusted files
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-09T23:17:06.740Z and was last modified on 2026-07-10T15:52:29.883Z. The evidence for this vulnerability comes from the official CVE record and NVD detail page. The affected product is Vim, a command line text editor. The vulnerability exists in the C omni-completion script in runtime/autoload/ccomplete.vim. The CVE record and NVD detail page provide additional information on the vulnerability, including its severity and potential impact. However, the record does not provide information on known affected scope or verified exploit attempts.

Sources and 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.