CVE-2023-40703

highpriority · track · 30EPSS 0.007 · 54 %ileDEEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.72% (54th) EPSS

CVSS 7.5 · high

Is it mine?

13 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · scored 2026-10-27

Mattermost fails to properly limit the characters allowed in different fields of a block in Mattermost Boards allowing a attacker to consume excessive resources, possibly leading to Denial of Service, by patching the field of a block using a specially crafted string.

cvss

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

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.3–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · ENISA EU

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · responsibledisclosure@mattermost.comexploitability 2.8 · impact 1.4

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Lsecondary · OSV

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

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

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-400USprimaryCWE-400US

affected products (13)

Products and version ranges known to be affected.

Mattermost Mattermost≤ 0 ≤9.1.0enisa_euvdEU
Mattermost Mattermost≤ 0 ≤8.1.3enisa_euvdEU
Mattermost Mattermost≤ 0 ≤9.0.1enisa_euvdEU
Mattermost Mattermostall versionsenisa_euvdEU
Mattermost Mattermost≤ 0 ≤7.8.12enisa_euvdEU
mattermost mattermost≤ 7.8.12nvdUScpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*
mattermost mattermost8.0.0 → 8.1.3nvdUScpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*
mattermost mattermost9.0.0 → 9.0.1nvdUScpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*
mattermost mattermost= 9.1.0nvdUScpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*
Go github.com/mattermost/mattermost-server/v6< 7.8.13osvUSpkg:golang/github.com/mattermost/mattermost-server/v6
Go github.com/mattermost/mattermost/server/v8< 8.1.4osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v89.0.0 → 9.0.2osvUSpkg:golang/github.com/mattermost/mattermost/server/v8
Go github.com/mattermost/mattermost/server/v89.1.0 → 9.1.1osvUSpkg:golang/github.com/mattermost/mattermost/server/v8

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-2763Mattermost: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2023-10-29csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Mattermost ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
GHSA-c37r-v8jx-7cv2Mattermost Uncontrolled Resource Consumption vulnerability2023-11-27ghsa · osvUS
Mattermost fails to properly limit the characters allowed in different fields of a block in Mattermost Boards allowing a attacker to consume excessive resources, possibly leading to Denial of Service, by patching the field of a block using a specially crafted string.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd osv cert_bund NVD CVE.org MITRE

published 2023-11-27modified 2026-06-17

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+9606 more

references (3)

External citations — patches, advisories, analysis.

scry

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