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Fencer Vulns
medium 4.9

CVE-2026-5308 json

Missing request body size limits on Zoom plugin HTTP endpoints

published 2026-05-22 5 mo ago modified 2026-07-23 3 mo ago also GHSA-jmvr-r5hm-fxfr , GO-2026-5836 , EUVD-2026-31425

cvss
4.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request body size limits on plugin HTTP endpoints which allows an attacker to cause a denial of service via crafted oversized HTTP requests.. Mattermost Advisory ID: MMSA-2026-00646

Patch / fix

  • go github.com/mattermost/mattermost-server 10.11.15, 10.11.15+incompatible, 11.4.5, 11.4.5+incompatible, 11.5.4, 11.5.4+incompatible, 11.6.1, 11.6.1+incompatible
  • go github.com/mattermost/mattermost-plugin-github 1.0.1-0.20260410143745-9b41b1fd43c4
  • Mattermost Mattermost 10.11.15, 11.4.5, 11.5.4, 11.6.1, 11.7.0
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go github.com/mattermost/mattermost-server
>=11.6.0, <11.6.1
>=11.5.0, <11.5.4
>=11.4.0, <11.4.5
>=10.11.0, <10.11.15
>=10.11.0+incompatible, <10.11.15+incompatible
>=11.4.0+incompatible, <11.4.5+incompatible
>=11.5.0+incompatible, <11.5.4+incompatible
>=11.6.0+incompatible, <11.6.1+incompatible
11.6.1
11.5.4
11.4.5
10.11.15
10.11.15+incompatible
11.4.5+incompatible
11.5.4+incompatible
11.6.1+incompatible
go github.com/mattermost/mattermost-plugin-github
<1.0.1-0.20260410143745-9b41b1fd43c4
1.0.1-0.20260410143745-9b41b1fd43c4

Affected products

  • Mattermost Mattermost

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

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.