Description

Hackney fails to properly release HTTP connections to the pool after handling 307 Temporary Redirect responses. Remote attackers can exploit this to exhaust connection pools, causing denial of service in applications using the library.
Fix for this issue has been included in 1.24.0 release.

Classification

CVE ID: CVE-2025-3864

CVSS Base Severity: LOW

CVSS Base Score: 2.3

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Affected Products

Vendor: hackney

Product: hackney

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.19% (probability of being exploited)

EPSS Percentile: 41.77% (scored less or equal to compared to others)

EPSS Date: 2025-06-26 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-3864
https://github.com/benoitc/hackney/issues/717
https://cert.pl/en/posts/2025/05/CVE-2025-3864/

Timeline