CVE-2026-2458
published 2026-03-16CVE-2026-2458: Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a…
PriorityP422medium4.3CVSS 3.1
AVNACLPRLUINSUCLINAN
EPSS
0.17%
6.1th percentile
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint.. Mattermost Advisory ID: MMSA-2025-00568
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github.com | mattermost_mattermost-server | >= 0 < 5.3.2-0.20260113182106-a18b80ba4c32 | 5.3.2-0.20260113182106-a18b80ba4c32 |
| github.com | mattermost_mattermost-server | >= 10.11.0-rc1 < 10.11.11 | 10.11.11 |
| github.com | mattermost_mattermost-server | >= 10.11.0-rc1+incompatible < 10.11.11+incompatible | 10.11.11+incompatible |
| github.com | mattermost_mattermost-server | >= 11.2.0-rc1 < 11.2.3 | 11.2.3 |
| github.com | mattermost_mattermost-server | >= 11.2.0-rc1+incompatible < 11.2.3+incompatible | 11.2.3+incompatible |
| github.com | mattermost_mattermost-server | >= 11.3.0-rc1 < 11.3.1 | 11.3.1 |
| github.com | mattermost_mattermost-server | >= 11.3.0-rc1+incompatible < 11.3.1+incompatible | 11.3.1+incompatible |
| github.com | mattermost_mattermost_server_v8 | >= 0 < 8.0.0-20260113182106-a18b80ba4c32 | 8.0.0-20260113182106-a18b80ba4c32 |
| mattermost | mattermost | 10.11.0 – 10.11.10 | — |
| mattermost | mattermost | 11.2.0 – 11.2.2 | — |
| mattermost | mattermost | 11.3.0 – 11.3.0 | — |
| mattermost | mattermost_server | >= 10.11.0 < 10.11.11 | 10.11.11 |
| mattermost | mattermost_server | >= 11.2.0 < 11.2.3 | 11.2.3 |
| mattermost | mattermost_server | >= 11.3.0 < 11.3.1 | 11.3.1 |
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OSV
Mattermost allows a removed team member to enumerate all public channels within a private team in github.com/mattermost/mattermost-server
osv·2026-03-23
CVE-2026-2458 Mattermost allows a removed team member to enumerate all public channels within a private team in github.com/mattermost/mattermost-server
Mattermost allows a removed team member to enumerate all public channels within a private team in github.com/mattermost/mattermost-server
Mattermost allows a removed team member to enumerate all public channels within a private team in github.com/mattermost/mattermost-server.
NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions.
(If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.)
The additional affected modules and versions are: github.com/mattermost/mattermost-server/v5 before v5.3.2-0.20260113182106-a18b80ba4c32.
OSV
Mattermost allows a removed team member to enumerate all public channels within a private team
osv·2026-03-16
CVE-2026-2458 [MEDIUM] Mattermost allows a removed team member to enumerate all public channels within a private team
Mattermost allows a removed team member to enumerate all public channels within a private team
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint. Mattermost Advisory ID: MMSA-2025-00568
GHSA
Mattermost allows a removed team member to enumerate all public channels within a private team
ghsa·2026-03-16
CVE-2026-2458 [MEDIUM] CWE-862 Mattermost allows a removed team member to enumerate all public channels within a private team
Mattermost allows a removed team member to enumerate all public channels within a private team
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint. Mattermost Advisory ID: MMSA-2025-00568
No detection rules found.
No public exploits indexed.
Wiz
CVE-2026-2458 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 4.3
CVE-2026-2458 [MEDIUM] CVE-2026-2458 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-2458 :
vulnerability analysis and mitigation
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint.. Mattermost Advisory ID: MMSA-2025-00568
Source : NVD
## 4.3
Score
Published March 16, 2026
Severity MEDIUM
CNA Score 4.3
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 8.4
Exploitation Probability (EPSS) N/A
Affected packages and libraries
github.com/mattermost/mattermost/server/v8
github.com/mattermost/mattermost-server
Sources
NVD
GoLang Severity MEDIUM Has
Bugzilla
CVE-2026-88829 busybox: busybox: HTTP request smuggling via pipelined requests in httpd reverse proxy [fedora-all]
bugzilla·2026-10-14·CVSS 7.2
CVE-2026-88829 [HIGH] CVE-2026-88829 busybox: busybox: HTTP request smuggling via pipelined requests in httpd reverse proxy [fedora-all]
CVE-2026-88829 busybox: busybox: HTTP request smuggling via pipelined requests in httpd reverse proxy [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
BusyBox httpd reverse proxy (CONFIG_FEATURE_HTTPD_PROXY, default enabled). When a P: rule matches, handle_incoming_and_exit() in networking/httpd.c rewrites only the first request line to the backend path (lines 2458-2462), sets G.POST_len = INT_MAX (line 2467), and enters cgi_io_loop_and_exit() (line 2468), which relays further client bytes to the backend without HTTP parsing. A pipelined second request on the same TCP connection therefore reaches the ba
2026-03-16
Published