CVE-2026-4858 json
Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.
published 5mo ago modified 3mo 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
Is CVE-2026-4858 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 5mo ago
Exploit prediction
0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-11).
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
-
mattermost.com
/security-updates
vendor-advisory, web
-
nvd.nist.gov
/vuln/detail/CVE-2026-4858
advisory
-
github.com
/mattermost/mattermost
package
-
github.com
/advisories/GHSA-c4r7-j7pp-r8mp
advisory
Sources
- CVE List CVE-2026-4858
- GitHub Advisory GHSA-c4r7-j7pp-r8mp
- NVD CVE-2026-4858
- OSV GO-2026-5311
Fencer Intel 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.