Pion/DTLS contains buffer for inbound DTLS fragments with no limitGHSA-cx94-mrg9-rq4j
MEDIUMFix: pion/dtls@a6397ffGHSA-cx94-mrg9-rq4j is a medium-severity (CVSS 5.3) CWE-120 vulnerability in github.com/pion/dtls. A fix is available for github.com/pion/dtls — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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 GHSA-cx94-mrg9-rq4j.
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/pion/dtls🐹github.com/pion/dtls/v2Real-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
Impact
A buffer that was used for inbound network traffic had no upper limit. Pion DTLS would buffer all network traffic from the remote user until the handshake completes or times out. An attacker could exploit this to cause excessive memory usage.
Patches
Upgrade to Pion DTLS v2.1.4
Workarounds
No workarounds available, upgrade to Pion DTLS v2.1.4
References
Thank you to Juho Nurminen and the Mattermost team for discovering and reporting this.
For more information
If you have any questions or comments about this advisory:
- Open an issue in Pion DTLS
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/pion/dtls | all versions | 2.1.4go get github.com/pion/dtls@v2.1.4 |
| 🐹Go | github.com/pion/dtls/v2 | all versions | 2.1.4go get github.com/pion/dtls/v2@v2.1.4 |
Affected Products
dtlspionDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/pion/dtls, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/pion/dtls to 2.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cx94-mrg9-rq4j 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.
Frequently Asked Questions
Is GHSA-cx94-mrg9-rq4j in your dependencies?
Find it across Go, including transitive dependencies.