HTML Injection while inviting Guests

published 2022-03-18 4 y ago modified 2026-06-17 4 mo ago also EUVD-2022-24352

cvss: 2.0; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits: 0; none known

Mattermost 6.3.0 and earlier fails to properly sanitize the HTML content in the email invitation sent to guest users, which allows registered users with special permissions to invite guest users to inject unescaped HTML content in the email invitations.

Patch / fix

fixed in 1

mattermost mattermost 6.4.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 23 mo ago (2024-12-06)

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

hackerone.com https://hackerone.com/reports/1443567 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	2.0	CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:L/A:N
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	3.5	AV:N/AC:M/Au:S/C:N/I:P/A:N

Affected products

Mattermost Mattermost

Classification

Weakness

CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page
CWE-79 Improper Neutralization of Input During Web Page Generation

References

hackerone.com /reports/1443567
exploit, third-party-advisory
mattermost.com /security-updates/
release-notes, vendor-advisory

Sources

CVE List CVE-2022-1002
NVD CVE-2022-1002

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.

Summary