CVE-2017-18904 json
Mattermost Server vulnerable to XSS via an uploaded file
published 2020-06-19 6 y ago modified 2026-06-17 4 mo ago also GHSA-8pff-p3gx-w4jf , GO-2026-4302 , EUVD-2017-9994
- cvss
- 6.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 53%
- public exploits
- 0
- none known
Summary
An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2. It allows XSS via an uploaded file.
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 0.0.20260114T191543-150000.1.137.1
suse advisories SUSE-SU-2026:0142-1
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
Exploit prediction
0.69% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
| GitHub | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost-server | <3.9.2 >=3.10.0, <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-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/mattermost/mattermost/commit/6a2754376c8c8270be5e11e3fdab589659d0cc8d
web
-
github.com
/mattermost/mattermost/commit/bde06a7bc3a03a56da224c1ffcd8bffb0af8071b
web
-
github.com
/mattermost/mattermost/commit/f06c5bef4d78966c60b153bbec6eea4ec0be9e68
web
-
mattermost.com
/security-updates/
vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2017-18904
advisory
-
github.com
/mattermost/mattermost
package
-
mattermost.com
/security-updates
web
-
github.com
/advisories/GHSA-8pff-p3gx-w4jf
advisory
Sources
- CVE List CVE-2017-18904
- GitHub Advisory GHSA-8pff-p3gx-w4jf
- NVD CVE-2017-18904
- OSV GO-2026-4302
Fencer Vulns 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.