CVE-2026-10819
Last modified
CVE-2026-10819 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Mattermost versions 11.6.x <= 11.6.5, 10.11.x <= 10.11.20, 11.8.x <= 11.8.1, 11.7.x <= 11.7.4 fail to limit the number of frames and enforce the file size cap on animated GIF uploads, which allows an authenticated attacker to cause a denial of service via a crafted animated GIF uploaded as a custom emoji.. Mattermost Advisory ID: MMSA-2026-00695. EPSS estimates a 0.24% chance of exploitation in the next 30 days.
Description
Mattermost versions 11.6.x <= 11.6.5, 10.11.x <= 10.11.20, 11.8.x <= 11.8.1, 11.7.x <= 11.7.4 fail to limit the number of frames and enforce the file size cap on animated GIF uploads, which allows an authenticated attacker to cause a denial of service via a crafted animated GIF uploaded as a custom emoji.. Mattermost Advisory ID: MMSA-2026-00695
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost Server | >= 10.11.0, < 10.11.21 |
| Mattermost | Mattermost Server | >= 11.6.0, < 11.6.6 |
| Mattermost | Mattermost Server | >= 11.7.0, < 11.7.5 |
| Mattermost | Mattermost Server | >= 11.8.0, < 11.8.2 |
References
- https://mattermost.com/security-updatesVendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-10819?
How severe is CVE-2026-10819?
How do I fix CVE-2026-10819?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-10813A flaw has been found in LMCache up to 0.4.6. This affects t…3.6
- CVE-2026-10814A vulnerability has been found in milvus-io milvus up to 2.6…7
- CVE-2026-10815A vulnerability was found in LakshayD02 Hostel-Management-Sy…6.3
- CVE-2026-10816Arbitrary File Read (Unauthenticated) in NetScaler ADC and N…7.5
- CVE-2026-10817Insufficient input validation leading to memory overread in …7.5
- CVE-2026-10818The WPForms Pro plugin for WordPress is vulnerable to Arbitr…8.1
- CVE-2026-1082The TITLE ANIMATOR plugin for WordPress is vulnerable to Cro…4.3
- CVE-2026-10820The Paid Membership Plugin, Ecommerce, User Registration For…8.1
- CVE-2026-10822If BIND encounters a particular invalid data structure in a …6.5
- CVE-2026-10823The YMC Filter WordPress plugin before 3.11.3 does not prope…7.5
- CVE-2026-10824The Masteriyo LMS WordPress plugin before 2.2.1 does not pe…6.5
- CVE-2026-10825A denial-of-service vulnerability exists in the WebSocket AP…7.1
Are you affected by CVE-2026-10819?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST