CVE-2017-18871

mediumpriority · track · 30EPSS 0.011 · 66 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.12% (66th) EPSS

CVSS 5 · medium

Is it mine?

13 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-28

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-248US

affected products (13)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
mattermost mattermost server< 4.2.2nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server4.3.0 → 4.3.4nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server4.4.0 → 4.4.5nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost server= 4.5.0nvdUScpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Go github.com/mattermost/mattermost-server< 4.2.2osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server< 4.2.2+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server4.3.0-rc1 → 4.3.4osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server4.3.0-rc1+incompatible → 4.3.4+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server4.4.0-rc1 → 4.4.5osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server4.4.0-rc1+incompatible → 4.4.5+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server4.5.0-rc1 → 4.5.0osvUSpkg:golang/github.com/mattermost/mattermost-server
Go github.com/mattermost/mattermost-server4.5.0-rc1+incompatible → 4.5.0+incompatibleosvUSpkg:golang/github.com/mattermost/mattermost-server

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-jc6w-8r7f-vmp5Mattermost Server vulnerable to Denial of Service through `@` character prefix inserted into JavaScript field names2022-05-24ghsa · osvUS
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.
GO-2025-4184Mattermost Server vulnerable to Denial of Service through `@` character prefix inserted into JavaScript field names in github.com/mattermost/mattermost-server2025-12-08vendor · osvUS
Mattermost Server vulnerable to Denial of Service through `@` character prefix inserted into JavaScript field names in github.com/mattermost/mattermost-server

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2020-06-19modified 2026-06-17

references (4)

External citations — patches, advisories, analysis.

scry

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