VulnerabilityAnalyzed
CVE-2025-5399
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.
HIGH 7.5EPSS 1.38%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.38% probability · 70th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-835
- Affected
- haxx/curl
- Source
- 2499f714-1537-4658-8207-48ae4bb9eae9
References
- https://curl.se/docs/CVE-2025-5399.htmlVendor Advisory
- https://curl.se/docs/CVE-2025-5399.jsonVendor Advisory
- https://hackerone.com/reports/3168039Exploit, Issue Tracking, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2025/06/04/2Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.