GHSA-v549-xx3c-6pc8

Suggest an improvement
Source
https://github.com/advisories/GHSA-v549-xx3c-6pc8
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-v549-xx3c-6pc8/GHSA-v549-xx3c-6pc8.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-v549-xx3c-6pc8
Aliases
Published
2026-05-18T09:31:47Z
Modified
2026-06-25T23:11:38Z
Severity
  • 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
Summary
Mattermost doesn't check the create_post channel permission during post edit operations
Details

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627

Database specific 
{
    "cwe_ids":  [
        "CWE-862"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-06-01T14:41:54Z",
    "nvd_published_at":  "2026-05-18T08:16:14Z",
    "severity":  "MODERATE"
}
References

Affected packages

Go
github.com/mattermost/mattermost/server/v8

Package

Name
github.com/mattermost/mattermost/server/v8
View open source insights on deps.dev
Purl
pkg:golang/github.com/mattermost/mattermost/server/v8

Affected ranges

Type
SEMVER
Events
Introduced
10.11.0
Fixed
10.11.14

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-v549-xx3c-6pc8/GHSA-v549-xx3c-6pc8.json"
github.com/mattermost/mattermost/server/v8

Package

Name
github.com/mattermost/mattermost/server/v8
View open source insights on deps.dev
Purl
pkg:golang/github.com/mattermost/mattermost/server/v8

Affected ranges

Type
SEMVER
Events
Introduced
11.4.0
Fixed
11.4.4

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-v549-xx3c-6pc8/GHSA-v549-xx3c-6pc8.json"
github.com/mattermost/mattermost/server/v8

Package

Name
github.com/mattermost/mattermost/server/v8
View open source insights on deps.dev
Purl
pkg:golang/github.com/mattermost/mattermost/server/v8

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
8.0.0-20260316171743-090408f09f53

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-v549-xx3c-6pc8/GHSA-v549-xx3c-6pc8.json"
github.com/mattermost/mattermost/server/v8

Package

Name
github.com/mattermost/mattermost/server/v8
View open source insights on deps.dev
Purl
pkg:golang/github.com/mattermost/mattermost/server/v8

Affected ranges

Type
SEMVER
Events
Introduced
11.5.0
Fixed
11.5.2

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-v549-xx3c-6pc8/GHSA-v549-xx3c-6pc8.json"
github.com/mattermost/mattermost-server

Package

Name
github.com/mattermost/mattermost-server
View open source insights on deps.dev
Purl
pkg:golang/github.com/mattermost/mattermost-server

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
5.3.2-0.20260316171743-090408f09f53

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-v549-xx3c-6pc8/GHSA-v549-xx3c-6pc8.json"