CVE-2026-102577: A flaw was found in Moodle

Routine

MEDIUM 4.3UPGRADE

CVE-2026-102577 is a medium-severity flaw (CVSS 4.3) affecting moodle. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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).

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 84%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-09-30
Last modified	2026-10-01

Publisher (CNA): Fedora Project · Vendor: moodle

Last updated 2026-10-01 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-30 09:17 UTCPublished CVE record published
2026-10-01 14:14 UTCUpdated Record last modified

moodle moodle UPGRADE

Affected: < 4.5.13 · >= 5.0.0 and < 5.0.9 · >= 5.1.0 and < 5.1.6 · >= 5.2.0 and < 5.2.2

Fixed in: 4.5.13, 5.0.9, 5.1.6, 5.2.2

Safe to downgrade to: a release before 5.0.0

1. Check installed version

apt-cache policy moodle || rpm -q moodle || moodle --version

2. UPGRADE to 4.5.13 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade moodle

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade moodle

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 5.0.0 (Debian / Ubuntu)

apt-cache madison moodle sudo apt install moodle=<VERSION_BEFORE_5.0.0> sudo apt-mark hold moodle

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list moodle sudo dnf downgrade moodle-<VERSION_BEFORE_5.0.0> sudo dnf versionlock add moodle

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-102577?

moodle: upgrade to 4.5.13, 5.0.9, 5.1.6, 5.2.2. Exact commands for each OS are on this page.

Is CVE-2026-102577 being exploited?

CVE-2026-102577 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-102577 affect?

CVE-2026-102577 affects moodle. Severity is medium (CVSS 4.3). 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 ca

How urgent is CVE-2026-102577?

Priority 19/100. No elevated risk signals yet.

Software pages

Moodle vulnerabilities

Related CVEs

CVE-2026-102588 MEDIUM 6.5 UPGRADE A flaw was found in Moodle
CVE-2026-102586 MEDIUM 4.3 UPGRADE A flaw was found in Moodle
CVE-2026-102581 MEDIUM 4.6 UPGRADE A flaw was found in Moodle
CVE-2026-102582 LOW 2.2 UPGRADE A flaw was found in Moodle
CVE-2026-102583 LOW 2.7 UPGRADE A flaw was found in Moodle

References

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