CVE-2026-96260
📛 CVE Title
Mattermost server missing request body size limit on plugin routes allows denial of service by an authenticated user
Description
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775
Overview
- State
- PUBLISHED
- Assigner (CNA)
- Mattermost
- CVSS severity
- MEDIUM
- CVSS score
- 6.5 / 10
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H- Effective score
- 6.5 / 10 MEDIUM source: CNA overview
- CWE(s)
-
CWE-789 - Reserved
- 2026-09-22
- Published
- 2026-09-22 20:34 UTC
- Last updated
- 2026-09-22 20:34 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/96xxx/CVE-2026-96260.json
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-09-22 21:17:35 UTC
- NVD last modified
- 2026-09-22 21:17:35 UTC
- NVD CVSS v3.1
- 6.5 / 10 MEDIUM source: responsibledisclosure@mattermost.com
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H- Exploitability subscore
- 2.8 / 10
- Impact subscore
- 3.6 / 10
NVD / KEV / EPSS data refreshed 2026-09-23 02:28 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-84870 - Assigner
- Mattermost
- Published
- Sep 22, 2026, 8:34:49 PM
- Updated
- Sep 22, 2026, 8:34:49 PM
- EUVD base score (CVSS 3.1)
-
6.5 / 10
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EUVD-reported EPSS
- 0.0000
- Vendors
- Mattermost
- Products
-
Mattermost (11.7.0 ≤11.7.10)Mattermost (11.9.0 ≤11.9.1)Mattermost (11.8.0 ≤11.8.5)Mattermost (11.10.0 ≤11.10.1)
- Aliases
-
GHSA-p28q-hqh3-qh95
ENISA description: Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Mattermost | Mattermost |
11.9.0 (affected),
11.8.0 (affected),
11.7.0 (affected),
11.10.0 (affected),
11.11.0 (unaffected),
11.9.2 (unaffected),
11.8.6 (unaffected),
11.7.11 (unaffected),
11.10.2 (unaffected)
|
— |
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
- MMSA-2026-00775 vendor-advisory
Web references (0)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
No web references attached yet.
NVD-tagged references (1)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://mattermost.com/security-updates responsibledisclosure@mattermost.com
Remediations (10)
-
web:connect.tenable.com
On September 8, Microsoft released its September 2026 Patch Tuesday release which patched 964 CVEs with 104 rated critical and 860 rated as important. This update includes patches for two zero-days that were exploited in the wild.
2026-09-23 15:39 UTC -
web:cybersecuritynews.com
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has issued Binding Operational Directive (BOD) 26-04, titled "Prioritizing Security Updates Based on Risk," compelling all Federal Civilian Executive Branch (FCEB) agencies to remediate the most dangerous known exploited vulnerabilities within just three calendar days.
2026-09-23 15:39 UTC -
web:sec.cloudapps.cisco.com
On September 16, 2026 , the Cisco Product Security Incident Response Team (PSIRT) published the advisories that are listed in the following tables. To remediate these vulnerabilities, Cisco strongly recommends that customers upgrade to the fixed software that is indicated in the advisories. For more information about changes in Cisco PSIRT vulnerability disclosure, see Strengthening the ...
2026-09-23 15:39 UTC -
web:senserva.com
Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.
2026-09-23 15:39 UTC -
web:windowsreport.com
Microsoft's September 2026 Patch Tuesday fixes a record 966 security vulnerabilities, including two zero-days that attackers are actively exploiting. Microsoft has released Patch Tuesday updates for Windows 11 alongside Windows 10 KB5122878, delivering what appears to be the company's largest Patch Tuesday security release to date.
2026-09-23 15:39 UTC -
web:www.cisecurity.org
<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...
2026-09-23 15:39 UTC -
web:www.oracle.com
This Critical Patch Update contains 1448 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at July 2026 Critical Patch Update: Executive Summary and Analysis.
2026-09-23 15:39 UTC -
web:www.oracle.com
Additional CVEs addressed are: The patch for CVE - 2026 -34481 also addresses CVE - 2026 -34477, CVE - 2026 -34478, CVE - 2026 -34479, and CVE - 2026 -34480. Oracle Fusion Middleware Risk Matrix This Critical Security Patch Update contains 106 new security patches for Oracle Fusion Middleware. 53 of these vulnerabilities may be remotely exploitable without authentication, i.e., may be exploited over a ...
2026-09-23 15:39 UTC -
web:www.techradar.com
Pro Security Cisco hit by max severity zero-day exploit targeting Identity Services Engine, so it's time to patch up News By Sead Fadilpašić Published September 17, 2026
2026-09-23 15:39 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's September 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-09-23 15:39 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-96260.json.
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Mattermost",
"vendor": "Mattermost",
"versions": [
{
"lessThanOrEqual": "11.9.1",
"status": "affected",
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"versionType": "semver"
},
{
"lessThanOrEqual": "11.8.5",
"status": "affected",
"version": "11.8.0",
"versionType": "semver"
},
{
"lessThanOrEqual": "11.7.10",
"status": "affected",
"version": "11.7.0",
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},
{
"lessThanOrEqual": "11.10.1",
"status": "affected",
"version": "11.10.0",
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},
{
"status": "unaffected",
"version": "11.11.0"
},
{
"status": "unaffected",
"version": "11.9.2"
},
{
"status": "unaffected",
"version": "11.8.6"
},
{
"status": "unaffected",
"version": "11.7.11"
},
{
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"version": "11.10.2"
}
]
}
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"descriptions": [
{
"lang": "en",
"value": "Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775"
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
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"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-789",
"description": "CWE-789: Memory Allocation with Excessive Size Value",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-22T20:34:49.141Z",
"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"shortName": "Mattermost"
},
"references": [
{
"name": "MMSA-2026-00775",
"tags": [
"vendor-advisory"
],
"url": "https://mattermost.com/security-updates"
}
],
"solutions": [
{
"lang": "en",
"value": "Update Mattermost to versions 11.11.0, 11.9.2, 11.8.6, 11.7.11, 11.10.2 or higher."
}
],
"source": {
"advisory": "MMSA-2026-00775",
"defect": [
"https://mattermost.atlassian.net/browse/MM-70503"
],
"discovery": "EXTERNAL"
},
"title": "Mattermost server missing request body size limit on plugin routes allows denial of service by an authenticated user",
"x_generator": {
"engine": "cvelib 1.8.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
"assignerShortName": "Mattermost",
"cveId": "CVE-2026-96260",
"datePublished": "2026-09-22T20:34:49.141Z",
"dateReserved": "2026-09-22T20:00:26.276Z",
"dateUpdated": "2026-09-22T20:34:49.141Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}