CVE Explorer
CVE-2026-6850
Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to validate the length and content of message attachment field values, which allows an authenticated attacker to cause a denial of service for all users in a channel via a post containing a specially crafted payload that triggers catastrophic backtracking in the client-side markdown parser.. Mattermost Advisory ID: MMSA-2026-00658
Known exploited
Not asserted
Disputed
No
Stale source
No
Conflicts
0
Affected products and versions
1 source assertion{"defaultStatus":"unaffected","product":"Mattermost","vendor":"Mattermost","versions":[{"lessThanOrEqual":"11.7.2","status":"affected","version":"11.7.0","versionType":"semver"},{"lessThanOrEqual":"11.6.4","status":"affected","version":"11.6.0","versionType":"semver"},{"lessThanOrEqual":"10.11.19","status":"affected","version":"10.11.0","versionType":"semver"},{"status":"unaffected","version":"11.8.0"},{"status":"unaffected","version":"11.7.3"},{"status":"unaffected","version":"11.6.5"},{"status":"unaffected","version":"10.11.20"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:f49a1761fe60be1b3fe99afc8c76109f67ccf2027c9d6c93624f92c6a10d19bb · sha256:1a403daa649788be… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:f49a1761fe60be1b3fe99afc8c76109f67ccf2027c9d6c93624f92c6a10d19bb · sha256:1a403daa649788be… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-1333","description":"CWE-1333: Inefficient Regular Expression Complexity","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:f49a1761fe60be1b3fe99afc8c76109f67ccf2027c9d6c93624f92c6a10d19bb · sha256:1a403daa649788be… · /containers/cna/problemTypes/0/descriptions/0
Source references
1 source assertion{"name":"MMSA-2026-00658","tags":["vendor-advisory"],"url":"https://mattermost.com/security-updates"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:f49a1761fe60be1b3fe99afc8c76109f67ccf2027c9d6c93624f92c6a10d19bb · sha256:1a403daa649788be… · /containers/cna/references/0
Attribution and limitations
- CVE Program CVEList V5: Reproduce the MITRE copyright designation and CVE license in copies. Source →
Provider severity values are preserved separately. Baitaphish does not convert them into a risk rating, infer affected products, or treat EPSS as observed exploitation.