CVE-2017-18898 json
Mattermost Server is vulnerable to DoS through maliciously crafted posts
published 2020-06-19 6 y ago modified 2026-06-17 4 mo ago also GHSA-9589-mq83-f749 , GO-2026-4300 , EUVD-2017-9988
- cvss
- 5.3
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.1%
- EPSS 1.1% chance of exploitation in 30 days, percentile 66%
- public exploits
- 0
- none known
Summary
An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5. It allows crafted posts that potentially cause a web browser to hang.
Patch / fix
- go github.com/mattermost/mattermost-server 4.0.5, 4.0.5+incompatible, 4.1.1, 4.1.1+incompatible, 4.2.0, 4.2.0+incompatible
- mattermost mattermost_server 4.0.5, 4.1.1
- 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
1.11% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/mattermost/mattermost-server | <4.0.5 >=4.1.0, <4.1.1 >=4.2.0-rc1, <4.2.0 <4.0.5+incompatible >=4.1.0+incompatible, <4.1.1+incompatible >=4.2.0-rc1+incompatible, <4.2.0+incompatible |
4.0.5 4.1.1 4.2.0 4.0.5+incompatible 4.1.1+incompatible 4.2.0+incompatible |
Classification
- Weakness
-
- CWE-404 Improper Resource Shutdown or Release
References
-
github.com
/grundleborg/mattermost/commit/5286318c72aa230f33f89df3b4cbdc33a0822a93
web
-
github.com
/mattermost/mattermost/commit/5bf6f06c02c368b9c73a8be2d2d8795b3405b22b
web
-
github.com
/mattermost/mattermost/commit/5c22176c963a7393241872073547f30083efe218
web
-
mattermost.com
/security-updates/
vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2017-18898
advisory
-
github.com
/mattermost/mattermost
package
-
mattermost.com
/security-updates
web
-
github.com
/advisories/GHSA-9589-mq83-f749
advisory
Sources
- CVE List CVE-2017-18898
- GitHub Advisory GHSA-9589-mq83-f749
- NVD CVE-2017-18898
- OSV GO-2026-4300
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.