What’s Vulnerable › Vulnerabilities

CVE-2026-102577: Moodle: ssrf risk in url downloader via ipv4-mapped ipv6 address bypass

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-30 · updated 2026-10-01
• Weakness: CWE-918

Description

A flaw was found in Moodle. Incorrect handling of IPv4-mapped IPv6 addresses within the URL downloader's host-blocking logic allows an authenticated remote user to bypass blocked-host restrictions. By supplying a crafted URL, an attacker can induce the server to make requests to restricted destinations, leading to Server-Side Request Forgery (SSRF).

Affected products

• Moodle: before 4.5.13; from 5.0.0 before 5.0.9; from 5.1.0 before 5.1.6; from 5.2.0 before 5.2.2 — fixed in 4.5.13, 5.0.9, 5.1.6, 5.2.2

How to fix

Upgrade to a fixed version: Moodle 4.5.13, 5.0.9, 5.1.6, 5.2.2. Check the vendor advisory for mitigations.

References

• http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-88779
• https://access.redhat.com/security/cve/CVE-2026-102577
• https://bugzilla.redhat.com/show_bug.cgi?id=2543604
• https://moodle.org/mod/forum/discuss.php?d=482495

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