CVE-2023-48268 — server
MEDIUMCVE-2023-48268 is a medium-severity (CVSS 4.3) Uncontrolled Resource Consumption vulnerability in github.com/mattermost/mattermost/server/v8. A fix is available for github.com/mattermost/mattermost/server/v8 — see the affected versions and patch details below.
Denial of Service via Board Import Zip Bomb
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-48268.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost-server/v6Real-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 limit the amount of data extracted from compressed archives during board import in Mattermost Boards allowing an attacker to consume excessive resources, possibly leading to Denial of Service, by importing a board using a specially crafted zip (zip bomb).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 9.1.0&&< 9.1.1 | 9.1.1go get github.com/mattermost/mattermost/server/v8@v9.1.1 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | ≥ 9.0.0&&< 9.0.2 | 9.0.2go get github.com/mattermost/mattermost/server/v8@v9.0.2 |
| 🐹Go | github.com/mattermost/mattermost/server/v8 | all versions | 8.1.4go get github.com/mattermost/mattermost/server/v8@v8.1.4 |
| 🐹Go | github.com/mattermost/mattermost-server/v6 | all versions | 7.8.13go get github.com/mattermost/mattermost-server/v6@v7.8.13 |
Affected Products
mattermostmattermostDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost/server/v8, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 CVE-2023-48268 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is CVE-2023-48268 in your dependencies?
Find it across Go, including transitive dependencies.