01 Record
CVE-2026-9708
Incoming webhook user attribution via unvalidated webhook owner
MediumPUBLISHEDCNA: Mattermost
CNA base score4.9 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
02 Description
Incoming webhook user attribution via unvalidated webhook owner
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
- 0.36% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 29.5% of scored records. A rank, not a probability.
- NVD base score
- 4.9 (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:N/I:H/A:N
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-07-13.
- 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
- 2026-07-13 08:00Z3 MO AGO
- Last updated
- 2026-07-13 14:45Z3 MO AGO
- Reserved
- 2026-05-27
- Assigning CNA
- Mattermost
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 4.9)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
- Weaknesses
- CWE-639Authorization Bypass Through User-Controlled KeyBase
- Data version
- 5.2
- Document digest
- a8959355ed351000a94a5e73a73dfaff2d9b723ba126acc61319413e2e1286a4
05 Affected products
VendorProductVersionsPlatforms
06 References
- mattermost.comMMSA-2026-00683https://mattermost.com/security-updates
07 Remediation
Update Mattermost to versions 11.8.0, 11.7.3, 11.6.5, 10.11.20 or higher.