CVE-2017-18903 json
Mattermost Server vulnerable to CSRF if CORS is enabled
published 2020-06-19 6 y ago modified 2026-06-17 4 mo ago also GHSA-fcwg-45jh-5qhf , GO-2026-4305 , EUVD-2017-9993
- cvss
- 8.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 37%
- public exploits
- 0
- none known
Summary
An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2. CSRF can occur if CORS is enabled.
Patch / fix
- go github.com/mattermost/mattermost-server 3.9.2, 3.9.2+incompatible, 3.10.2, 3.10.2+incompatible
- mattermost mattermost_server 3.9.2, 3.10.2
- govulncheck-vulndb openSUSE Leap 15.6 0.0.20260226T182644-150000.1.149.1
suse advisories SUSE-SU-2026:0757-1
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
Exploit prediction
0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 5.1 | AV:N/AC:H/Au:N/C:P/I:P/A:P |
| GitHub | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost-server | <3.9.2 >=3.10.0-rc1, <3.10.2 <3.9.2+incompatible >=3.10.0+incompatible, <3.10.2+incompatible |
3.9.2 3.10.2 3.9.2+incompatible 3.10.2+incompatible |
Classification
- Weakness
-
- CWE-352 Cross-Site Request Forgery
References
-
github.com
/mattermost/mattermost/commit/312269ad0bd166174f07f9df7391fce714601600
web
-
github.com
/mattermost/mattermost/commit/4519b03d95e8bfe1b2f74094673ae1a2f39f6b47
web
-
github.com
/mattermost/mattermost/commit/a18479df0940be8503c9b88993490741793eba9e
web
-
mattermost.com
/security-updates/
vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2017-18903
advisory
-
github.com
/mattermost/mattermost
package
-
mattermost.com
/security-updates
web
-
github.com
/advisories/GHSA-fcwg-45jh-5qhf
advisory
Sources
- CVE List CVE-2017-18903
- GitHub Advisory GHSA-fcwg-45jh-5qhf
- NVD CVE-2017-18903
- OSV GO-2026-4305
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.