CVE-2026-0999

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.17% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 6.9% of scored records. A rank, not a probability.

NVD base score

4.3 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-02-16 09:47Z6 MO AGO

Last updated

2026-02-17 16:53Z6 MO AGO

Reserved

2026-01-15

Assigning CNA

Mattermost

Record state

PUBLISHED

Severity

Medium (CVSS 5.4)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Weaknesses

• CWE-303Incorrect Implementation of Authentication AlgorithmBase

Data version

5.2

Document digest

9725a6fe3c9053561252b15b4aa72e550074ab1f4fd21cf408454e4e19ff34d2

• mattermost.comMMSA-2025-00548https://mattermost.com/security-updatesvendor-advisory