CVE-2026-2456

mediumpriority · track · 23EPSS 0.002 · 6 %ileDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.17% (6th) EPSS
CVSS 5.7 · medium
Is it mine?
36 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button.. Mattermost Advisory ID: MMSA-2026-00571

01

cvss

Technical severity, 0–10. One row per scoring source.

5.7
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.7mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.1 · impact 3.6
v3.15.7mediumAV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.15.3mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · ENISA EU
v3.15.3mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · responsibledisclosure@mattermost.comexploitability 1.6 · impact 3.6
v3.15.3mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · OSV
v3.15.2mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-400USCWE-789USCWE-789US
04

affected products (36)

Products and version ranges known to be affected.

showing 20 of 36
05

advisories (3)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-0422Mattermost: Mehrere SchwachstellenDeutsch2026-02-15csaf · cert_bundDE

    Ein authentisierter Angreifer kann mehrere Schwachstellen in Mattermost ausnutzen, um falsche Informationen anzuzeigen, Informationen offenzulegen, Sicherheitskontrollen zu umgehen und eine Denial-of-Service-Situation zu erzeugen.

  • GHSA-34g8-9fpp-46chMattermost fails to limit the size of responses from integration action endpoints2026-03-16ghsa · osvUS

    Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button. Mattermost Advisory ID: MMSA-2026-00571

  • GO-2026-4726Mattermost fails to limit the size of responses from integration action endpoints in github.com/mattermost/mattermost-server2026-03-26vendor · osvUS

    Mattermost fails to limit the size of responses from integration action endpoints 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 v5.3.2-0.20260127165411-fe3052073dc6.

06

also known as (6)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bduosvcert_bundNVDCVE.orgMITRE
published 2026-03-16modified 2026-06-17
08

references (3)

External citations — patches, advisories, analysis.

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