TI-2026-21052 Aliases CVE-2026-26047 GHSA-cg8j-5cr2-568q

Moodle: moodle: uncontrolled resource consumption in tex formula editor leading to denial of service

LOW 29CWE-400Published 2026-02-21 · Updated 2026-02-23

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00506 43rd percentileScored 2026-11-07

Fix Fixed moodle: 4.5.9, 5.0.5, 5.1.2moodle/moodle (Packagist): 5.1.2, 5.0.5, 4.5.9

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	moodle	before 4.5.9; 5.0.0 to before 5.0.5; 5.1.0 to before 5.1.2	4.5.9, 5.0.5, 5.1.2	Patch available	CNA
—	moodle/moodle (Packagist)	5.1.0-beta to before 5.1.2	5.1.2	Patch available	GHSA-cg8j-5cr2-568q
—	moodle/moodle (Packagist)	5.0.0-beta to before 5.0.5	5.0.5	Patch available	GHSA-cg8j-5cr2-568q
—	moodle/moodle (Packagist)	before 4.5.9	4.5.9	Patch available	GHSA-cg8j-5cr2-568q

moodle Vendor— Affected before 4.5.9; 5.0.0 to before 5.0.5; 5.1.0 to before 5.1.2 Fixed in 4.5.9, 5.0.5, 5.1.2 Patch available CNA
moodle/moodle (Packagist) Vendor— Affected 5.1.0-beta to before 5.1.2 Fixed in 5.1.2 Patch available GHSA-cg8j-5cr2-568q
moodle/moodle (Packagist) Vendor— Affected 5.0.0-beta to before 5.0.5 Fixed in 5.0.5 Patch available GHSA-cg8j-5cr2-568q
moodle/moodle (Packagist) Vendor— Affected before 4.5.9 Fixed in 4.5.9 Patch available GHSA-cg8j-5cr2-568q

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:moodle:moodle::::::::	before 4.5.9; 5.0.0 to before 5.0.5; 5.1.0 to before 5.1.2	Vulnerable	Moodle

cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:* Versions before 4.5.9; 5.0.0 to before 5.0.5; 5.1.0 to before 5.1.2 Vulnerable ·Moodle

Remediation

Fix · CNA moodle Fixed in 4.5.9, 5.0.5, 5.1.2
Fix · GHSA-cg8j-5cr2-568q moodle/moodle (Packagist) Fixed in 5.1.2 Advisory →
Fix · GHSA-cg8j-5cr2-568q moodle/moodle (Packagist) Fixed in 5.0.5 Advisory →
Fix · GHSA-cg8j-5cr2-568q moodle/moodle (Packagist) Fixed in 4.5.9 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product

Red Hat

Timeline

2026-10-02 Threatist record created from CVE-2026-26047
2026-10-03 Alias added: GHSA-cg8j-5cr2-568q
2026-10-19 EPSS moved to the 50th–90th percentile
2026-10-25 EPSS moved to the below the 50th percentile

References

Advisory 3

Other 3

TI-2024-22468 moodle: unsafe direct use of $_SERVER['HTTP_REFERER'] in admin/tool/mfa/index.php CVSS 3.1CRITICAL 9.8
TI-2021-14741 In Moodle, an SQL injection risk was identified in the library fetching a user's recent courses. CVSS 3.1CRITICAL 9.8
TI-2024-29071 Moodle: remote code execution via calculated question types CVSS 3.1HIGH 8.1
TI-2016-06653 Moodle 3.1.2 allows remote attackers to obtain sensitive information via unspecified… CVSS 3.1HIGH 7.5
TI-2022-00259 SQL injection in moodle CVSS 3.1CRITICAL 9.8
TI-2022-16116 Path traversal in Moodle CVSS 3.1HIGH 7.5

See all 636 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences