CVE-2026-5740
- Source
- https://cve.org/CVERecord?id=CVE-2026-5740
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-5740.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-5740
- Aliases
- Published
- 2026-05-22T10:22:01.030Z
- Modified
- 2026-07-08T08:13:52.337897617Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- Unauthenticated WebSocket binary frame causes denial of service in Mattermost Server
- Details
-
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to properly validate msgpack-encoded WebSocket frames before memory allocation which allows an unauthenticated remote attacker to crash the server process and cause a full service outage for all users via a crafted binary WebSocket message sent to the public WebSocket endpoint.. Mattermost Advisory ID: MMSA-2026-00647
- Database specific
{ "unresolved_ranges": [ { "source": "AFFECTED_FIELD", "extracted_events": [ { "introduced": "11.6.0" }, { "last_affected": "11.6.0" }, { "introduced": "11.5.0" }, { "last_affected": "11.5.3" }, { "introduced": "11.4.0" }, { "last_affected": "11.4.4" }, { "introduced": "10.11.0" }, { "last_affected": "10.11.14" } ] } ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5740.json", "cwe_ids": [ "CWE-789" ], "cna_assigner": "Mattermost" }- References
Affected packages
Git / github.com/mattermost/mattermost
Affected ranges
- Type
- GIT
- Repo
- https://github.com/mattermost/mattermost
- Events
-
IntroducedFixedIntroducedFixedIntroducedFixedIntroducedFixed
- Database specific
{ "source": "CPE_RANGE", "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "extracted_events": [ { "introduced": "10.11.0" }, { "fixed": "10.11.15" }, { "introduced": "11.4.0" }, { "fixed": "11.4.5" }, { "introduced": "11.5.0" }, { "fixed": "11.5.4" }, { "introduced": "11.6.0" }, { "fixed": "11.6.1" } ] }
Affected versions
@mattermost/client@10.*
@mattermost/client@10.11.0
@mattermost/client@11.*
@mattermost/client@11.4.0
@mattermost/types@10.*
@mattermost/types@10.11.0
@mattermost/types@11.*
@mattermost/types@11.4.0
mattermost-redux@10.*
mattermost-redux@10.11.0
mattermost-redux@11.*
mattermost-redux@11.4.0
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
v10.11.2
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.*
v11.4.0
v11.4.0-rc3
v11.4.1
v11.4.1-rc1
v11.4.1-rc2
v11.4.2
v11.4.3
v11.4.4
v11.5.0
v11.5.1
v11.5.2
v11.5.2-rc1
v11.5.2-rc2
v11.5.2-rc3
v11.5.3
v11.6.0