CVE-2026-6850
- Source
- https://cve.org/CVERecord?id=CVE-2026-6850
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6850.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-6850
- Downstream
- Published
- 2026-07-13T08:13:02.883Z
- Modified
- 2026-08-12T03:51:41.915491375Z
- Severity
-
- 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- Crafted message attachment causes client-side denial of service via markdown parser regex backtracking in Mattermost
- Details
-
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
- Database specific
{ "unresolved_ranges": [ { "source": "AFFECTED_FIELD", "extracted_events": [ { "introduced": "11.7.0" }, { "last_affected": "11.7.2" }, { "introduced": "11.6.0" }, { "last_affected": "11.6.4" }, { "introduced": "10.11.0" }, { "last_affected": "10.11.19" } ] } ], "cwe_ids": [ "CWE-1333" ], "cna_assigner": "Mattermost", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6850.json" }- 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": "10.11.0" }, { "fixed": "10.11.20" }, { "introduced": "11.6.0" }, { "fixed": "11.6.5" }, { "introduced": "11.7.0" }, { "fixed": "11.7.3" } ] }
Affected versions
@mattermost/client@10.*
@mattermost/client@10.11.0
@mattermost/client@11.*
@mattermost/client@11.7.0
@mattermost/shared@11.*
@mattermost/shared@11.7.0
@mattermost/types@10.*
@mattermost/types@10.11.0
@mattermost/types@11.*
@mattermost/types@11.7.0
mattermost-redux@10.*
mattermost-redux@10.11.0
mattermost-redux@11.*
mattermost-redux@11.7.0
v10.*
v10.11.0
v10.11.0-rc3
v10.11.1
v10.11.1-rc1
v10.11.10
v10.11.11
v10.11.11-rc1
v10.11.11-rc2
v10.11.12
v10.11.13
v10.11.13-rc1
v10.11.14
v10.11.14-rc1
v10.11.15
v10.11.15-rc1
v10.11.16
v10.11.17
v10.11.18
v10.11.19
v10.11.19-rc1
v10.11.2
v10.11.2-rc1
v10.11.2-rc2
v10.11.3
v10.11.4
v10.11.4-rc1
v10.11.4-rc2
v10.11.4-rc3
v10.11.5
v10.11.6
v10.11.7
v10.11.8
v10.11.9
v10.11.9-rc1
v11.*
v11.6.0
v11.6.1
v11.6.1-rc1
v11.6.2
v11.6.3
v11.6.4
v11.7.0
v11.7.1
v11.7.2