CVE-2026-19600Mattermost logs plaintext authentication tokens in debug-level server logs on failed auth attempts
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No exploitation reported and no EPSS estimate yet.
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Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to sanitize authentication tokens before writing them to server log entries, which allows an attacker with access to server logs to obtain valid session tokens or OAuth access tokens and impersonate authenticated users via the debug-level Mattermost server log.. Mattermost Advisory ID: MMSA-2026-00763
- CVSS
- 4.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-532
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Mattermost
- NVD analysis
- Received
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 16, 2026
Affected products
Mattermost Mattermost mattermost:mattermost (from the name) | from 11.9.0 through 11.9.1; from 11.8.0 through 11.8.5; from 11.7.0 through 11.7.10; from 11.10.0 through 11.10.1; 11.11.0 not affected; 11.9.2 not affected; 11.8.6 not affected; 11.7.11 not affected; and 1 more ranges | CNA record |
References
- https://mattermost.com/security-updatesvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.