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Fencer Vulns
high 8.0

CVE-2026-4858 json

Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.

published 2026-05-21 5 mo ago modified 2026-07-23 3 mo ago also GHSA-c4r7-j7pp-r8mp , GO-2026-5311 , EUVD-2026-31242

cvss
8.0
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 26%
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 check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL.. Mattermost Advisory ID: MMSA-2026-00640

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
  • 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
total
Assessed
5 mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.0 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
NVD 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
GitHub 3.1 8.0 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/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

Affected products

  • Mattermost Mattermost

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

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.