Mattermost Server password reset email requests can be sent to attacker-provided email addresses

Also known as GHSA-34cx-hvm4-vx7j, GO-2026-4476

Published 6 y ago 2020-06-19 · modified 4 mo ago 2026-06-17 · JSON

CVSS

9.8

v3.1 · NVD

CISA KEV

not known exploited

EPSS

1.2%

percentile 68%

Public exploits

none known

An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2. A password-reset request was sometime sent to an attacker-provided e-mail address.

Exploit prediction (EPSS)

1.18% probability of exploitation in the next 30 days, higher than 68% of all scored CVEs.

CVSS scores

Assigned by	Version	Score	Vector
NVD	3.1	9.8	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
NVD	2.0	7.5	`AV:N/AC:L/Au:N/C:P/I:P/A:P`
GitHub	3.1	9.8	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

Affected packages

Ecosystem	Package	Affected	Fixed in
go	`github.com/mattermost/mattermost-server`	<3.9.1-rc1 >=3.10.0, <3.10.1 <3.9.1-rc1+incompatible >=3.10.0+incompatible, <3.10.1+incompatible	3.9.1-rc1 3.10.1 3.9.1-rc1+incompatible 3.10.1+incompatible

Classification

Weakness

CWE-287 Improper Authentication
CWE-640 Weak Password Recovery Mechanism for Forgotten Password

References

mattermost.com /security-updates/ · x_refsource_CONFIRM, x_transferred
nvd.nist.gov /vuln/detail/CVE-2017-18908 · advisory
github.com /mattermost/mattermost/commit/59139390ae927af2e879dbacfe4dadb1adac97c0 · web
github.com /mattermost/mattermost/commit/d3bc11be3acd3a73e6358d958b91427e2584ea71 · web
github.com /mattermost/mattermost/commit/e5065cf7575ee05c040945a4b00b7fd90bf39b83 · web
github.com /mattermost/mattermost · package
mattermost.com /security-updates · web
github.com /advisories/GHSA-34cx-hvm4-vx7j · advisory

Sources

CVE List: CVE-2017-18908
GitHub Advisory: GHSA-34cx-hvm4-vx7j
NVD: CVE-2017-18908
OSV: GO-2026-4476

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