01 Record
CVE-2026-6334
OAuth authorization code client binding not enforced during token redemption in Mattermost
LowPUBLISHEDCNA: Mattermost
CNA base score3.1 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N
02 Description
OAuth authorization code client binding not enforced during token redemption in Mattermost
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.11% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 1.5% of scored records. A rank, not a probability.
- NVD base score
- 3.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-10-14.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-05-18 06:33Z5 MO AGO
- Last updated
- 2026-05-18 14:36Z5 MO AGO
- Reserved
- 2026-04-15
- Assigning CNA
- Mattermost
- Record state
- PUBLISHED
- Severity
- Low (CVSS 3.1)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N
- Weaknesses
- CWE-305Authentication Bypass by Primary WeaknessBase
- Data version
- 5.2
- Document digest
- ab89568cba7adb2dcada559ec71c3598f1dde13b0ff522c5e9560fff3c645e80
05 Affected products
VendorProductVersionsPlatforms
06 References
- mattermost.comMMSA-2026-00570https://mattermost.com/security-updates
07 Remediation
Update Mattermost to versions 11.6.0, 11.5.2, 10.11.14 or higher.