Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.26% for the current model date.
BlackTreeCVE IntelligenceMattermost · Mattermost
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| gogithub.com/mattermost/mattermost-plugin-jira | < 4.4.1 | 4.4.1 | GitHub advisory ↗github reviewed aggregator · 2 Jan 2026 |
| gogithub.com/mattermost/mattermost/server/v8 | < 8.0.0-20251121122154-b57c297c6d7a | 8.0.0-20251121122154-b57c297c6d7a | GitHub advisory ↗github reviewed aggregator · 2 Jan 2026 |
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch availableMattermost versions 11.1.x <= 11.1.0, 11.0.x <= 11.0.5, 10.12.x <= 10.12.3, 10.11.x <= 10.11.7 with the Jira plugin enabled and Mattermost Jira plugin versions <=4.4.0 fail to enforce authentication and issue-key path restrictions in the Jira plugin, which allows an unauthenticated attacker who knows a valid user ID to issue authenticated GET and POST requests to the Jira server via crafted plugin payloads that spoof the user ID and inject arbitrary issue key paths. Mattermost Advisory ID: MMSA-2025-00555
Mattermost versions 11.1.x <= 11.1.0, 11.0.x <= 11.0.5, 10.12.x <= 10.12.3, 10.11.x <= 10.11.7 with the Jira plugin enabled and Mattermost Jira plugin versions <=4.4.0 fail to enforce authentication and issue-key path restrictions in the Jira plugin, which allows an unauthenticated attacker who knows a valid user ID to issue authenticated GET and POST requests to the Jira server via crafted plugin payloads that spoof the user ID and inject arbitrary issue key paths. Mattermost Advisory ID: MMSA-2025-00555
The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
Mattermost versions 11.1.x <= 11.1.0, 11.0.x <= 11.0.5, 10.12.x <= 10.12.3, 10.11.x <= 10.11.7 with the Jira plugin enabled and Mattermost Jira plugin versions <=4.4.0 fail to enforce authentication and issue-key path restrictions in the Jira plugin, which allows an unauthenticated attacker who knows a valid user ID to issue authenticated GET and POST requests to the Jira server via crafted plugin payloads that spoof the user ID and inject arbitrary issue key paths. Mattermost Advisory ID: MMSA-2025-00555
The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-303: Incorrect Implementation of Authentication Algorithm. The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:LCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 22 Dec 2025 · Last source change 22 Dec 2025, 12:59 UTC · CWE-303 · Incorrect Implementation of Authentication Algorithm
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.