How severe is CVE-2021-21376?

CVE-2021-21376 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-21376 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21376?

CVE-2021-21376 affects Openmicroscopy Omero.web. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21376?

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

When was CVE-2021-21376 published?

CVE-2021-21376 was published on 2021-03-23 and last updated on 2026-06-17.

CVE-2021-21376

CVE-2021-21376 is a medium-severity vulnerability in Openmicroscopy Omero.web with a CVSS 3.x base score of 6.4. 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 6.4)
CVSS v2: 5.0
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Openmicroscopy Omero.web
Published: 2021-03-23
Last modified: 2026-06-17

Description

OMERO.web is open source Django-based software for managing microscopy imaging. OMERO.web before version 5.9.0 loads various information about the current user such as their id, name and the groups they are in, and these are available on the main webclient pages. This represents an information exposure vulnerability. Some additional information being loaded is not used by the webclient and is being removed in this release. This is fixed in version 5.9.0.

Frequently asked questions

What is CVE-2021-21376?: OMERO.web is open source Django-based software for managing microscopy imaging. OMERO.web before version 5.9.0 loads various information about the current user such as their id, name and the groups they are in, and these are available on the main webclient pages. This represents an information exposure vulnerability. Some additional information being loaded is not used by the webclient and is being removed in this release. This is fixed in version 5.9.0.
How severe is CVE-2021-21376?: CVE-2021-21376 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-21376 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21376?: CVE-2021-21376 affects Openmicroscopy Omero.web. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21376?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-21376 published?: CVE-2021-21376 was published on 2021-03-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:openmicroscopy:omero.web:*:*:*:*:*:*:*:*

More vulnerabilities in Openmicroscopy Omero.web

CVE-2020-7932 — Medium (CVSS 5.7): OMERO.web before 5.6.3 optionally allows sensitive data elements (e.g., a session key) to be passed as URL query…
CVE-2021-21377 — Medium (CVSS 4.8): OMERO.web is open source Django-based software for managing microscopy imaging. OMERO.web before version 5.9.0 supports…

All CVEs affecting Openmicroscopy Omero.web →

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 →