CVE-2026-4273 json
Insufficient token rotation validation in remote cluster invite confirmation
published 2026-05-18 5 mo ago modified 2026-10-14 25 d ago also GHSA-hqpj-f3jh-29vx , GO-2026-5432 , EUVD-2026-30740
- cvss
- 3.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 3%
- public exploits
- 0
- none known
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
Patch / fix
- go github.com/mattermost/mattermost/server/v8 8.0.0-20260313190740-742e0be95074, 10.11.14, 11.5.2
- go github.com/mattermost/mattermost-server 5.3.2-0.20260313190740-742e0be95074, 10.11.14+incompatible, 11.5.2+incompatible
- Mattermost Mattermost 10.11.14, 11.5.2, 11.6.0
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
| NVD | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
| GitHub | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost/server/v8 | >=11.5.0, <11.5.2 >=10.11.0, <10.11.14 <8.0.0-20260313190740-742e0be95074 |
11.5.2 10.11.14 8.0.0-20260313190740-742e0be95074 |
| go | github.com/mattermost/mattermost-server | <5.3.2-0.20260313190740-742e0be95074 >=10.11.0+incompatible, <10.11.14+incompatible >=11.5.0+incompatible, <11.5.2+incompatible |
5.3.2-0.20260313190740-742e0be95074 10.11.14+incompatible 11.5.2+incompatible |
| go | github.com/mattermost/mattermost-server/v5 | all versions |
no fix listed |
| go | github.com/mattermost/mattermost-server/v6 | all versions |
no fix listed |
Affected products
- Mattermost Mattermost
Classification
- Weakness
-
- CWE-863 Incorrect Authorization
References
Sources
- CVE List CVE-2026-4273
- GitHub Advisory GHSA-hqpj-f3jh-29vx
- NVD CVE-2026-4273
- OSV GO-2026-5432
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