How severe is CVE-2023-49809?

CVE-2023-49809 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 none, integrity none, and availability low.

Is CVE-2023-49809 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-49809?

CVE-2023-49809 affects Mattermost Mattermost Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-49809?

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

When was CVE-2023-49809 published?

CVE-2023-49809 was published on 2023-12-12 and last updated on 2026-06-17.

CVE-2023-49809

CVE-2023-49809 is a medium-severity vulnerability in Mattermost Mattermost Server 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-400.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Mattermost Mattermost Server
Published: 2023-12-12
Last modified: 2026-06-17

Description

Mattermost fails to handle a null request body in the /add endpoint, allowing a simple member to send a request with null request body to that endpoint and make it crash. After a few repetitions, the plugin is disabled.

Frequently asked questions

What is CVE-2023-49809?: Mattermost fails to handle a null request body in the /add endpoint, allowing a simple member to send a request with null request body to that endpoint and make it crash. After a few repetitions, the plugin is disabled.
How severe is CVE-2023-49809?: CVE-2023-49809 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 none, integrity none, and availability low.
Is CVE-2023-49809 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-49809?: CVE-2023-49809 affects Mattermost Mattermost Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-49809?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-49809 published?: CVE-2023-49809 was published on 2023-12-12 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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