Server-side Denial of Service while processing a specifically crafted GIF file

published 2022-09-23 4 y ago modified 2026-06-17 4 mo ago also BIT-mattermost-2022-3257 , EUVD-2022-6874 , GHSA-m7w4-q5vg-5xfp

cvss: 3.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 69%
public exploits: 0; none known

Mattermost version 7.1.x and earlier fails to sufficiently process a specifically crafted GIF file when it is uploaded while drafting a post, which allows authenticated users to cause resource exhaustion while processing the file, resulting in server-side Denial of Service.

Patch / fix

fixed in 3

go github.com/mattermost/mattermost-server/v6 7.2.0
bitnami mattermost 7.2.0
mattermost mattermost_server 7.2.0

CISA SSVC

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

Exploit prediction

1.26% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

hackerone.com https://hackerone.com/reports/1620170 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	3.1	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
GitHub	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
OSV	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
go	github.com/mattermost/mattermost-server/v6	>=7.1.0, <7.2.0	7.2.0
bitnami	mattermost	<7.2.0	7.2.0

Affected products

Mattermost Mattermost

Classification

Weakness

CWE-400 Uncontrolled Resource Consumption
CWE-434 Unrestricted Upload of File with Dangerous Type

References

hackerone.com /reports/1620170
web, exploit, third-party-advisory
mattermost.com /security-updates/
vendor-advisory, web
nvd.nist.gov /vuln/detail/CVE-2022-3257
advisory, web
github.com /mattermost/mattermost-server
package
mattermost.com /security-updates
web

Sources

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