Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-27659— CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint

Quick assessment

Affected
Mattermost Mattermost
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Mattermost是美国Mattermost公司的一个开源协作平台。 Mattermost 11.2.2及之前的11.2.x版本、10.11.10及之前的10.11.x版本、11.4.0及之前的11.4.x版本和11.3.1及之前的11.3.x版本存在安全漏洞，该漏洞源于/api/v4/access_control_policies/{policy_id}/activate端点中CSRF令牌验证不当，可能导致攻击者诱骗管理员通过特制请求更改访问控制策略活动状态。

CVSS 4.6 · Medium EPSS 0.22% · P11

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-27659

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
CSRF vulnerability in UpdateAccessControlPolicyActiveStatus endpoint
Source: CVE Program / CVE List V5
Vulnerability Description
Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
跨站请求伪造(CSRF)
Source: CVE Program / CVE List V5
Vulnerability Title
Mattermost 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Mattermost是美国Mattermost公司的一个开源协作平台。 Mattermost 11.2.2及之前的11.2.x版本、10.11.10及之前的10.11.x版本、11.4.0及之前的11.4.x版本和11.3.1及之前的11.3.x版本存在安全漏洞，该漏洞源于/api/v4/access_control_policies/{policy_id}/activate端点中CSRF令牌验证不当，可能导致攻击者诱骗管理员通过特制请求更改访问控制策略活动状态。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Mattermost Mattermost 11.2.0 ~ 11.2.2 -

II. Public POCs for CVE-2026-27659

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-27659

请登录查看更多情报信息。

Same Patch Batch · Mattermost · 2026-03-25 · 4 CVEs total

CVE-2026-27656 5.7 MEDIUM Account Takeover via Substring Matching in OpenID Connect Authentication
CVE-2026-26233 4.3 MEDIUM Denial of Service via HTTP/2 single packet attack on login endpoint
CVE-2026-20719 4.3 MEDIUM DoS via URL Previews Rendering Malicious SVGs

IV. Related Vulnerabilities

Same product: Mattermost
Same vendor: Mattermost
Same weakness: CWE-352

V. Comments for CVE-2026-27659

No comments yet

Leave a comment