CVE-2017-18871
No exploitation reported by the sources we read.
- Published2020-06-19
- Fixed in4.5.0+incompatible · 4.5.0 · 4.4.5 · 4.4.5+incompatible · 4.3.4 · 4.3.4+incompatible
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
An issue was discovered in Mattermost Server before 4.5.0, 4.4.5, 4.3.4, and 4.2.2. It allows attackers to cause a denial of service (application crash) via an @ character before a JavaScript field name.
Timeline
dates in UTC- 2020-06-1917:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2017-18871?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2017-18871?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
OSV · NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 4.5 | ≥ 4.5.0-rc1+incompatible, < 4.5.0+incompatible | 4.5.0+incompatible | OSV |
| 4.5 | ≥ 4.5.0-rc1, < 4.5.0 | 4.5.0 | OSV |
| 4.4 | ≥ 4.4.0, < 4.4.5 | 4.4.5 | NVD |
| 4.4 | ≥ 4.4.0-rc1+incompatible, < 4.4.5+incompatible | 4.4.5+incompatible | OSV |
| 4.4 | ≥ 4.4.0-rc1, < 4.4.5 | 4.4.5 | OSV |
| 4.3 | ≥ 4.3.0, < 4.3.4 | 4.3.4 | NVD |
| 4.3 | ≥ 4.3.0-rc1+incompatible, < 4.3.4+incompatible | 4.3.4+incompatible | OSV |
| 4.3 | ≥ 4.3.0-rc1, < 4.3.4 | 4.3.4 | OSV |
| 4.2 | < 4.2.2 | 4.2.2 | NVD · OSV |
| 4.2 | < 4.2.2+incompatible | 4.2.2+incompatible | OSV |
| 4.5 | = 4.5.0 | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
- Update Mattermost mattermost server to 4.5.0+incompatible · 4.5.0 · 4.4.5 · 4.4.5+incompatible · 4.3.4 · 4.3.4+incompatible · 4.2.2 · 4.2.2+incompatible
Advisories and patches
- mattermost.comVendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- NVDCVSS 3.17.5read 2026-10-23
- NVDCVSS 2.05read 2026-10-23
- FIRST EPSSEPSS score1.1 %2026-10-23
- OSVaffected packages—
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2020-06-19
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2017-18871?
Is CVE-2017-18871 actively exploited?
What is the CVSS score for CVE-2017-18871?
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