CVE-2026-4273

ℹ️ low

Summary

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a crafted invite confirmation with a RefreshedToken matching the original token. Mattermost Advisory ID: MMSA-2026-00575

CVSS Score

3.7

Low

EPSS Score

0.0

Exploit Probability

Published Date

2026-05-18

First Seen: 2026-05-19

📊 Relative Risk Intelligence

This CVE is Lower Risk - more severe than 4.0% of all 327,350 vulnerabilities in our database.

#314,298

Below average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: May 18, 2026

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

Requires human interaction

💥 Technical Impact

Partial

Limited system impact

🏆 Discovered By

daw10

SSVC data provided by CISA

Last Modified 2026-05-19

Source NVD 🔗

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

CWE IDs (Weakness Types)

CWE-863

📦 Affected Products 2

Vendor	Product	Status	Affected Versions
mattermost	mattermost_server	Affected	> 10.11.0 < 10.11.14
mattermost	mattermost_server	Affected	> 11.5.0 < 11.5.2

🔗 References 1

https://mattermost.com/security-updates

Vendor Advisory

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-4915	🔶 medium	6.5	0.1	Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to filter nil element...	2026-05-25
CVE-2026-3473	🔶 medium	5.9	0.0	Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate file owne...	2026-05-22
CVE-2026-3636	🔶 medium	4.3	0.0	Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team memb...	2026-05-22
CVE-2026-4635	🔶 medium	6.5	0.0	Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to archive the channe...	2026-05-22
CVE-2026-4646	🔶 medium	4.3	0.1	Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supp...	2026-05-22
CVE-2026-5308	🔶 medium	4.9	0.1	Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request bo...	2026-05-22

These CVEs affect the same products