# CVE-2026-102577: Moodle SSRF in URL downloader IPv4-mapped IPv6 bypass

Source: https://junglewise.ai/threats/cve-2026-102577-a-flaw-was-found-in-moodle-incorrect-handling-of-ipv4-mapped  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-30. Updated: 2026-09-30  
License: CC BY 4.0 with a link back

CVE-2026-102577 · Severity: medium · CVSS 4.3 · Published 2026-09-30

Moodle, an open-source learning management system used by educational institutions worldwide, contains a flaw in its URL downloader's security controls. An authenticated attacker can bypass host-blocking restrictions by using IPv4-mapped IPv6 addresses, potentially allowing them to access internal systems or private networks from the Moodle server—an attack known as Server-Side Request Forgery. This could lead to unauthorized access to sensitive data or internal services.

Technologies: [Moodle](https://junglewise.ai/threats/technologies/moodle). Vendors: [Moodle](https://junglewise.ai/threats/vendors/moodle).

## Quick answers

**Is CVE-2026-102577 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-102577 being exploited in the wild.

**How severe is CVE-2026-102577?** Medium severity, with a CVSS score of 4.3, published 30 September 2026.

**Which products and versions are affected?** Moodle Moodle.

**Is there a fix for CVE-2026-102577?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-102577 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-102577?** Check whether you run Moodle. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in Moodle's URL downloader component, which fails to properly validate IPv4-mapped IPv6 addresses (e.g., ::ffff:127.0.0.1) against the configured host-blocking allowlist. An authenticated remote attacker can craft a URL using this format to bypass the restriction logic and cause the server to make requests to blocked destinations. This is a classic SSRF attack vector requiring authentication as a precondition.

## Affected products

- Moodle Moodle

## Timeline

- 2026-09-30: disclosed

## References

- [https://git.moodle.org/](https://git.moodle.org/)
- [http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-88779](http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-88779)

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- [Moodle path traversal in Blackboard question import](https://junglewise.ai/threats/cve-2026-119553-moodle-5-3-0-5-2-0-through-5-2-4-5-1-0-through-5-1-8-5-0-0)