Moodle TeX formula editor is vulnerable to DoS through lack of execution time limits
CVE-2026-26047GHSA-cg8j-5cr2-568q
What to do
Vendor fix available. Upgrade each affected package to the fixed version on its release line (moodle/moodle 5.1.2, 5.0.5, 4.5.9), redeploy, then verify what is actually installed.
This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.
Affected packages
Packagist moodle/moodle
- Affected
- >= 5.1.0-beta, < 5.1.2>= 5.0.0-beta, < 5.0.5< 4.5.9
- Fixed in
- 5.0.5, 4.5.9, 5.1.2
Sources
- GitHub Advisory Database and maintainer security advisories on GitHub
GitHub-reviewed advisory GHSA-cg8j-5cr2-568q lists affected ranges: Packagist moodle/moodle >=5.1.0-beta =5.0.0-beta =0 <4.5.9
VerifiedObserved Structured GitHub Advisory Database record (type=reviewed) from the GitHub REST API.
Severity and exploitation
- Exploitation
- No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
- CVSS
- 6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- CVE-2026-26047: 0.51% estimated exploitation activity in the next 30 days; percentile 43.24 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description
As published by the source; long descriptions are shortened.
A Denial of Service vulnerability was identified in Moodle’s TeX formula editor. When rendering TeX content using mimetex, insufficient execution time limits could allow specially crafted formulas to consume excessive server resources. An authenticated user could abuse this behavior to degrade performance or cause service interruption.
Dates and revisions
- Published by the source
- Last modified by the source
- Source last checked
- Revision 1 · created ·
Published from ghsa record GHSA-cg8j-5cr2-568q
Agent brief
Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.
# Patch Next advisory brief: CVE-2026-26047 Advisory: Moodle TeX formula editor is vulnerable to DoS through lack of execution time limits IDs: CVE-2026-26047, GHSA-cg8j-5cr2-568q Record: https://patchnext.com/advisories/cve-2026-26047 (revision 1, source checked 26 Oct 2026, 14:38 UTC) Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected. Severity: Medium (CVSS 6.5) Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV. Vendor response: Vendor fix available; fixed versions by package: moodle/moodle 5.1.2, 5.0.5, 4.5.9. A vendor fix does not mean a deployment is fixed. ## Affected components - Packagist moodle/moodle: affected >= 5.1.0-beta, < 5.1.2; >= 5.0.0-beta, < 5.0.5; < 4.5.9; fixed in 5.0.5, 4.5.9, 5.1.2 ## Suggested inspection (read-only) - Packagist moodle/moodle: check the installed version with your package manager. ## Supported action Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version. ## Required regression checks - Run the test suite and a production build. - Exercise the features that depend on moodle/moodle. - Repeat the inspection and confirm that only fixed versions remain installed. ## Rollback considerations - Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward. ## Unresolved questions - Which deployments run an affected version? - Exploitation status can change. Check again before lowering the priority. - Mark the work resolved only after the fixed version is verified in production. ## Sources - Verified: https://github.com/advisories/GHSA-cg8j-5cr2-568q (GitHub-reviewed advisory GHSA-cg8j-5cr2-568q lists affected ranges: Packagist moodle/moodle >=5.1.0-beta =5.0.0-beta =0 <4.5.9) Commands are suggestions: review each one before running it.
Loading voting…