How severe is CVE-2016-2156?

CVE-2016-2156 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-2016-2156 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-2156?

CVE-2016-2156 primarily affects Moodle. In total, 33 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-2156?

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

When was CVE-2016-2156 published?

CVE-2016-2156 was published on 2016-05-22 and last updated on 2026-06-17.

CVE-2016-2156

CVE-2016-2156 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.0
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Moodle
Published: 2016-05-22
Last modified: 2026-06-17

Description

calendar/externallib.php in Moodle through 2.6.11, 2.7.x before 2.7.13, 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 provides calendar-event data without considering whether an activity is hidden, which allows remote authenticated users to obtain sensitive information via a web-service request.

Frequently asked questions

What is CVE-2016-2156?: calendar/externallib.php in Moodle through 2.6.11, 2.7.x before 2.7.13, 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 provides calendar-event data without considering whether an activity is hidden, which allows remote authenticated users to obtain sensitive information via a web-service request.
How severe is CVE-2016-2156?: CVE-2016-2156 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-2016-2156 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-2156?: CVE-2016-2156 primarily affects Moodle. In total, 33 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-2156?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-2156 published?: CVE-2016-2156 was published on 2016-05-22 and last updated on 2026-06-17.

References

Affected products (33)

cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.0:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.1:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.2:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.3:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.4:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.5:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.6:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.7:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.8:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.9:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.10:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.11:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.7.12:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.0:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.1:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.2:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.3:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.4:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.5:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.6:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.7:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.8:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.9:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.8.10:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.9.0:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.9.1:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.9.2:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.9.3:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.9.4:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:3.0.0:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:3.0.1:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:3.0.2:*:*:*:*:*:*:*

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-200 (Exposure of Sensitive Information to an Unauthorized Actor) vulnerabilities

CVE-2026-27604 — Critical (CVSS 10.0): FOSSBilling is a free, open-source billing and client management system. Starting in version 0.5.4 and prior to version…
CVE-2026-40965 — Critical (CVSS 10.0): Cloud Foundry UAA versions v76.12.0 through v78.12.0 are vulnerable to a private key exposure. The server contains a…
CVE-2026-42826 — Critical (CVSS 10.0): Exposure of sensitive information to an unauthorized actor in Azure DevOps allows an unauthorized attacker to disclose…
CVE-2025-29270 — Critical (CVSS 10.0): Incorrect access control in the realtime.cgi endpoint of Deep Sea Electronics devices DSE855 v1.1.0 to v1.1.26 allows…
CVE-2025-61481 — Critical (CVSS 10.0): An issue in MikroTik RouterOS v.7.14.2 and SwOS v.2.18 exposes the WebFig management interface over cleartext HTTP by…
CVE-2025-53624 — Critical (CVSS 10.0): The Docusaurus gists plugin adds a page to your Docusaurus instance, displaying all public gists of a GitHub user.…

Browse all CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) vulnerabilities →