Vulnerability Description
Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the application to escape or exit this loop other than killing the thread/process. This might be used to DoS libcurl-using application.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Haxx | Curl | >= 8.13.0, < 8.14.1 |
Related Weaknesses (CWE)
References
- https://curl.se/docs/CVE-2025-5399.htmlVendor Advisory
- https://curl.se/docs/CVE-2025-5399.jsonVendor Advisory
- https://hackerone.com/reports/3168039ExploitIssue TrackingThird Party Advisory
- http://www.openwall.com/lists/oss-security/2025/06/04/2Mailing ListThird Party Advisory
FAQ
What is CVE-2025-5399?
CVE-2025-5399 is a vulnerability with a CVSS score of 7.5 (HIGH). Due to a mistake in libcurl's WebSocket code, a malicious server can send a particularly crafted packet which makes libcurl get trapped in an endless busy-loop. There is no other way for the applicat...
How severe is CVE-2025-5399?
CVE-2025-5399 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-5399?
Check the references section above for vendor advisories and patch information. Affected products include: Haxx Curl.