01 Record
CVE-2026-10819
Mattermost Server Denial of Service via Animated GIF Emoji Upload
MediumPUBLISHEDCNA: Mattermost
CNA base score6.5 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
02 Description
Mattermost Server Denial of Service via Animated GIF Emoji Upload
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
- 0.42% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 36.0% of scored records. A rank, not a probability.
- NVD base score
- 6.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-08-03.
- 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
- 2026-07-27 14:15Z3 MO AGO
- Last updated
- 2026-07-27 15:05Z3 MO AGO
- Reserved
- 2026-06-04
- Assigning CNA
- Mattermost
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.5)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-409Improper Handling of Highly Compressed Data (Data Amplification)Base
- Data version
- 5.2
- Document digest
- 1e9200e643865eefa4f447b8d2bd062dad8b3bf4802ae7a56333b038befeb0c1
05 Affected products
VendorProductVersionsPlatforms
06 References
- mattermost.comMMSA-2026-00695https://mattermost.com/security-updates
07 Remediation
Update Mattermost to versions 11.9.0, 11.6.6, 10.11.21, 11.8.2, 11.7.5 or higher.