How severe is CVE-2025-55073?

CVE-2025-55073 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2025-55073 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-55073?

CVE-2025-55073 affects Mattermost Mattermost Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-55073?

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

Does CVE-2025-55073 have an EU (EUVD) identifier?

Yes. CVE-2025-55073 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-186555.

When was CVE-2025-55073 published?

CVE-2025-55073 was published on 2025-11-14 and last updated on 2026-06-17.

CVE-2025-55073

CVE-2025-55073 is a medium-severity vulnerability in Mattermost Mattermost Server with a CVSS 3.x base score of 5.4. 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-306.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-186555
Weakness: CWE-306
Affected product: Mattermost Mattermost Server
Published: 2025-11-14
Last modified: 2026-06-17

Description

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL.

Frequently asked questions

What is CVE-2025-55073?: Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL.
How severe is CVE-2025-55073?: CVE-2025-55073 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2025-55073 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-55073?: CVE-2025-55073 affects Mattermost Mattermost Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-55073?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-55073 have an EU (EUVD) identifier?: Yes. CVE-2025-55073 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-186555.
When was CVE-2025-55073 published?: CVE-2025-55073 was published on 2025-11-14 and last updated on 2026-06-17.

References

https://mattermost.com/security-updates

Affected products (1)

cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*

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