CVE-2026-6334 (GCVE-0-2026-6334)
Vulnerability from cvelistv5 – Published: 2026-05-18 06:33 – Updated: 2026-05-18 14:36
VLAI
EPSS
VEX
Title
OAuth authorization code client binding not enforced during token redemption in Mattermost
Summary
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to enforce client identity binding during the OAuth authorization code redemption flow which allows an authenticated OAuth client to redeem authorization codes issued to a different client via a crafted token exchange request.. Mattermost Advisory ID: MMSA-2026-00570
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-18 14:36 UTC
CWE
- CWE-305 - – Authentication Bypass by Primary Weakness
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Mattermost | Mattermost |
Affected:
11.5.0 , ≤ 11.5.1
(semver)
Affected: 10.11.0 , ≤ 10.11.13 (semver) Unaffected: 11.6.0 Unaffected: 11.5.2 Unaffected: 10.11.14 |
guessed |
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