How severe is CVE-2023-28334?

CVE-2023-28334 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2023-28334 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-28334?

CVE-2023-28334 primarily affects Moodle. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-28334?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-28334 published?

CVE-2023-28334 was published on 2023-03-23 and last updated on 2026-06-17.

CVE-2023-28334

CVE-2023-28334 is a medium-severity vulnerability in Moodle with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-639
Affected product: Moodle
Published: 2023-03-23
Last modified: 2026-06-17

Description

Authenticated users were able to enumerate other users' names via the learning plans page.

Frequently asked questions

What is CVE-2023-28334?: Authenticated users were able to enumerate other users' names via the learning plans page.
How severe is CVE-2023-28334?: CVE-2023-28334 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2023-28334 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-28334?: CVE-2023-28334 primarily affects Moodle. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-28334?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-28334 published?: CVE-2023-28334 was published on 2023-03-23 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:4.0.0:-:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:4.1.0:-:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:4.1.1:*:*:*:*:*:*:*

More vulnerabilities in Moodle

CVE-2006-4935 — Critical (CVSS 10.0): The Database module in Moodle before 1.6.2 does not properly handle uploaded files, which has unspecified impact and…
CVE-2006-4936 — Critical (CVSS 10.0): Moodle before 1.6.2 does not properly validate the module instance id when creating a course module object, which has…
CVE-2005-2247 — Critical (CVSS 10.0): Multiple unknown vulnerabilities in Moodle before 1.5.1 have unknown impact and attack vectors.
CVE-2004-2233 — Critical (CVSS 10.0): Unknown "front page vulnerability with Moodle servers" for Moodle before 1.3.2 has unknown impact and attack vectors.
CVE-2004-2236 — Critical (CVSS 10.0): Unknown vulnerability in Moodle before 1.3.3 has unknown impact and attack vectors, related to language setting.
CVE-2004-2237 — Critical (CVSS 10.0): Unknown vulnerability in Moodle before 1.3.4 has unknown impact and attack vectors, related to "strings in Moodle…

All CVEs affecting Moodle →

Other CWE-639 (Authorization Bypass Through User-Controlled Key (IDOR)) vulnerabilities

CVE-2025-40805 — Critical (CVSS 10.0): Affected devices do not properly enforce user authentication on specific API endpoints. This could facilitate an…
CVE-2024-45032 — Critical (CVSS 10.0): A vulnerability has been identified in Industrial Edge Management Pro (All versions < V1.9.5), Industrial Edge…
CVE-2026-34037 — Critical (CVSS 9.9): Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Prior to…
CVE-2026-52782 — Critical (CVSS 9.9): OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, there is an IDOR through…
CVE-2026-45552 — Critical (CVSS 9.9): Roxy-WI is a web interface for managing Haproxy, Nginx, Apache and Keepalived servers. In versions 8.2.6.4 and prior,…
CVE-2026-29200 — Critical (CVSS 9.9): A critical IDOR vulnerability has been discovered in Comet Backup affecting all versions from 20.11.0 to 26.1.1 and…

Browse all CWE-639 (Authorization Bypass Through User-Controlled Key (IDOR)) vulnerabilities →