CVE-2026-6339
- Source
- https://cve.org/CVERecord?id=CVE-2026-6339
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6339.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-6339
- Aliases
- Downstream
- Related
- Published
- 2026-05-18T08:05:30.925Z
- Modified
- 2026-08-12T03:51:25.692049756Z
- Severity
-
- 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
- Summary
- Missing request origin validation on burn-on-read reveal endpoint
- Details
-
Mattermost versions 11.5.x <= 11.5.1, 11.4.x <= 11.4.3 fail to validate the X-Requested-With header on the burn-on-read reveal endpoint which allows an authenticated channel member to force the reveal of a burn-on-read message without recipient consent via a crafted Markdown image tag.. Mattermost Advisory ID: MMSA-2026-00636
- Database specific
{ "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6339.json", "unresolved_ranges": [ { "source": "AFFECTED_FIELD", "extracted_events": [ { "introduced": "11.5.0" }, { "last_affected": "11.5.1" }, { "introduced": "11.4.0" }, { "last_affected": "11.4.3" } ] } ], "cwe_ids": [ "CWE-346" ], "cna_assigner": "Mattermost" }- References
Affected packages
Git / github.com/mattermost/mattermost
Affected ranges
- Type
- GIT
- Repo
- https://github.com/mattermost/mattermost
- Events
- Database specific
-
Show details
{ "source": "CPE_RANGE", "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "extracted_events": [ { "introduced": "11.4.0" }, { "fixed": "11.4.4" }, { "introduced": "11.5.0" }, { "fixed": "11.5.2" } ] }