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PatchSiren cyber security CVE debrief

CVE-2026-52858 vim CVE debrief

CVE-2026-52858 is a high-severity vulnerability in Vim's Python omni-completion script. The vulnerability exists in python3complete.vim for Vim with the +python3 interpreter enabled and in pythoncomplete.vim for builds with the +python interpreter. When a user opens a hostile .py file with a sibling Python package and invokes omni-completion, it runs that package's top-level code as the editing user. This issue has been patched in version 9.2.0561.

Vendor
vim
Product
Unknown
CVSS
HIGH 7.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-11
Original CVE updated
2026-06-15
Advisory published
2026-06-11
Advisory updated
2026-06-15

Who should care

Users of Vim with the +python3 or +python interpreter enabled should be aware of this vulnerability. Specifically, developers and users who work with Python files in Vim and use the omni-completion feature are at risk.

Technical summary

The Python omni-completion script in python3complete.vim and pythoncomplete.vim executes import and from statements found in the current buffer through Python's import machinery. Because the buffer's working directory is on sys.path, opening a hostile .py file with a sibling Python package and invoking omni-completion runs that package's top-level code as the editing user.

Defensive priority

High

Recommended defensive actions

  • Update Vim to version 9.2.0561 or later.
  • Avoid opening untrusted .py files in Vim with the +python3 or +python interpreter enabled.
  • Use caution when invoking omni-completion on Python files from untrusted sources.

Evidence notes

CVE-2026-52858 has a CVSS score of 7.3 and is classified as HIGH severity. The vulnerability is related to CWE-94, CWE-95, and CWE-829.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-52858 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-52858

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

  • CVE-2026-52858 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-52858

    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.