How severe is GHSA-c37r-v8jx-7cv2?

GHSA-c37r-v8jx-7cv2 has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-c37r-v8jx-7cv2?

GHSA-c37r-v8jx-7cv2 affects the following packages: github.com/mattermost/mattermost/server/v8 (Go), github.com/mattermost/mattermost/server/v8 (Go), github.com/mattermost/mattermost/server/v8 (Go), github.com/mattermost/mattermost-server/v6 (Go). Ecosystems affected: Go.

How do I fix GHSA-c37r-v8jx-7cv2?

Update github.com/mattermost/mattermost/server/v8 to 9.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c37r-v8jx-7cv2 is resolved across your whole dependency graph.

How do I detect GHSA-c37r-v8jx-7cv2 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost/server/v8. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-c37r-v8jx-7cv2 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-c37r-v8jx-7cv2?

O3 pinpoints whether GHSA-c37r-v8jx-7cv2 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-c37r-v8jx-7cv2 actively exploited in the wild?

No public exploit code has been indexed for GHSA-c37r-v8jx-7cv2 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is GHSA-c37r-v8jx-7cv2?

GHSA-c37r-v8jx-7cv2 is classified as Uncontrolled Resource Consumption (CWE-400). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-c37r-v8jx-7cv2 published, and has it been updated?

GHSA-c37r-v8jx-7cv2 was published on November 27, 2023 and was last updated on February 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

GHSA-c37r-v8jx-7cv2

MEDIUM

GHSA-c37r-v8jx-7cv2 is a medium-severity (CVSS 4.3) Uncontrolled Resource Consumption vulnerability in github.com/mattermost/mattermost/server/v8. O3 Security confirms whether GHSA-c37r-v8jx-7cv2 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Mattermost Uncontrolled Resource Consumption vulnerability

Also known asCVE-2023-40703

Published

Nov 27, 2023

Updated

Feb 4, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Blast Radius

4 pkgs affected

🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost-server/v6

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/mattermost/mattermost/server/v8`	≥ 9.1.0&&< 9.1.1	9.1.1
🐹Go	`github.com/mattermost/mattermost/server/v8`	≥ 9.0.0&&< 9.0.2	9.0.2
🐹Go	`github.com/mattermost/mattermost/server/v8`	all versions	8.1.4
🐹Go	`github.com/mattermost/mattermost-server/v6`	all versions	7.8.13

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost/server/v8. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/mattermost/mattermost/server/v8 to 9.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c37r-v8jx-7cv2 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-c37r-v8jx-7cv2 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-c37r-v8jx-7cv2. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is GHSA-c37r-v8jx-7cv2 in your dependencies?

O3 detects GHSA-c37r-v8jx-7cv2 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works