CVE Explorer
CVE-2026-20796
Mattermost versions 10.11.x <= 10.11.9 fail to properly validate channel membership at the time of data retrieval which allows a deactivated user to learn team names they should not have access to via a race condition in the /common_teams API endpoint.. Mattermost Advisory ID: MMSA-2025-00549
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":"10.11.9","status":"affected","version":"10.11.0","versionType":"semver"},{"status":"unaffected","version":"11.3.0"},{"status":"unaffected","version":"10.11.10"}]}
- cve_program_cvelist_v5affectedurn:baitaphish:normalized-source-record:v2:b4f3fd95a044ca784636b2723fee5c6761b2e452a4fc78f8d23c90e4943c9452 · sha256:a212417e16d9f680… · /containers/cna/affected/0
Provider-owned CVSS observations
1 source assertion{"metric":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":3.1,"baseSeverity":"LOW","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/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:b4f3fd95a044ca784636b2723fee5c6761b2e452a4fc78f8d23c90e4943c9452 · sha256:a212417e16d9f680… · /containers/cna/metrics/0/cvssV3_1
CWE assertions
1 source assertion{"cweId":"CWE-367","description":"CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition","lang":"en","type":"CWE"}
- cve_program_cvelist_v5cweurn:baitaphish:normalized-source-record:v2:b4f3fd95a044ca784636b2723fee5c6761b2e452a4fc78f8d23c90e4943c9452 · sha256:a212417e16d9f680… · /containers/cna/problemTypes/0/descriptions/0
Source references
1 source assertion{"name":"MMSA-2025-00549","tags":["vendor-advisory"],"url":"https://mattermost.com/security-updates"}
- cve_program_cvelist_v5referenceurn:baitaphish:normalized-source-record:v2:b4f3fd95a044ca784636b2723fee5c6761b2e452a4fc78f8d23c90e4943c9452 · sha256:a212417e16d9f680… · /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.