Cyber Resilience

CVE-2025-14273

Auth Bypass in Mattermost Server 10.11.0 – 10.11.8

Published
22 December 2025
Modified
29 December 2025
Patch / advisory
CVSS Score v3.1 7.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L
EPSS Score 0.0024 15th percentile
Risk Priority 52 floored blend · peak EPSS

Summary

CVE-2025-14273 is a high-severity Incorrect Implementation of Authentication Algorithm (CWE-303) vulnerability in Mattermost Mattermost Server. Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique External Remote Services (T1133); ranked at the 15th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-14273 is a vulnerability in the Mattermost Jira plugin that fails to enforce authentication and issue-key path restrictions. It affects Mattermost versions 11.1.x up to and including 11.1.0, 11.0.x up to and including 11.0.5, 10.12.x up to and including 10.12.3, and 10.11.x up to and including 10.11.7 when the Jira plugin versions up to and including 4.4.0 is enabled. The issue, tied to CWE-303 (Incorrect Implementation of Authentication and Session Management), has a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L) and is documented under Mattermost Advisory ID MMSA-2025-00555.

An unauthenticated attacker who knows a valid Mattermost user ID can exploit this by crafting plugin payloads that spoof the user ID and inject arbitrary issue key paths. This enables the attacker to issue authenticated GET and POST requests to the connected Jira server on behalf of the spoofed user, potentially allowing unauthorized access or manipulation of Jira issues.

For mitigation details, refer to the Mattermost security advisory MMSA-2025-00555 available at https://mattermost.com/security-updates.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

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CVE-2025-12419Same product: Mattermost Mattermost Server
CVE-2026-27656Same product: Mattermost Mattermost Server
CVE-2025-3230Same product: Mattermost Mattermost Server
CVE-2025-2475Same product: Mattermost Mattermost Server
CVE-2025-55070Same product: Mattermost Mattermost Server
CVE-2026-6673Same product: Mattermost Mattermost Server
CVE-2025-13870Same product: Mattermost Mattermost Server

Affected Assets

mattermost
mattermost server
10.11.0 — 10.11.8 · 10.12.0 — 10.12.4 · 11.0.0 — 11.0.6

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation at post-design stages directly uncovers incorrect implementations of required authentication algorithms.

Requiring documented development processes, standards, and tools reduces the chance that an established authentication algorithm is coded incorrectly.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require correct implementation of authentication algorithms.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

degrades

Secure authentication control directly requires correct implementation of authentication algorithms.

finds

Security testing can detect flawed authentication implementations but does not prevent them by itself.

degrades

Cryptography control addresses proper use of authentication algorithms but is broader than authentication alone.

prevents

Secure development lifecycle includes verification steps that can catch incorrect authentication implementations.

prevents

Application security requirements can specify correct authentication algorithm use but do not guarantee correct implementation.

prevents

Secure coding practices reduce the likelihood of incorrect authentication algorithm implementation.

References