CVE Explorer
CVE-2026-21386
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to use consistent error responses when handling the /mute command which allows an authenticated team member to enumerate private channels they are not authorized to know about via differing error messages for nonexistent versus private channels. Mattermost Advisory ID: MMSA-2026-00588
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":"11.3.0","status":"affected","version":"11.3.0","versionType":"semver"},{"lessThanOrEqual":"11.2.2","status":"affected","version":"11.2.0","versionType":"semver"},{"lessThanOrEqual":"10.11.10","status":"affected","version":"10.11.0","versionType":"semver"},{"status":"unaffected","version":"11.4.0"},{"status":"unaffected","version":"11.3.1"},{"status":"unaffected","version":"11.2.3"},{"status":"unaffected","version":"10.11.11"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:5aadfe9a7d07db0ce49e0059e49d7d2fb6b77d5c0cb6736b95fb51a5fdd5bf50 · sha256:0ee1115b9c5a3dc1… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","version":"3.1"},"metric_type":"cvssV3_1"}
- cve_program_cvelist_v5cvssurn:baitaphish:normalized-source-record:v2:5aadfe9a7d07db0ce49e0059e49d7d2fb6b77d5c0cb6736b95fb51a5fdd5bf50 · sha256:0ee1115b9c5a3dc1… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-203","description":"CWE-203: Observable Discrepancy","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:5aadfe9a7d07db0ce49e0059e49d7d2fb6b77d5c0cb6736b95fb51a5fdd5bf50 · sha256:0ee1115b9c5a3dc1… · /containers/cna/problemTypes/0/descriptions/0
Source references
1 source assertion{"name":"MMSA-2026-00588","tags":["vendor-advisory"],"url":"https://mattermost.com/security-updates"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:5aadfe9a7d07db0ce49e0059e49d7d2fb6b77d5c0cb6736b95fb51a5fdd5bf50 · sha256:0ee1115b9c5a3dc1… · /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.