CVE-2025-3864
Connection pool exhaustion in hackney
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Connection pool exhaustion in hackney
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.
- Record
CVE-2025-3864- CVSS 4.0
- 2.3 Low
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 - Weakness
- CWE-772
- Updated
- 2026-11-02
EUVDEUVD-2025-16328
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.
- Record
EUVD-2025-16328- CVSS 4.0
- 2.3 Low
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-9fm9-hp7p-53mf
Hackney fails to properly release HTTP connections to the pool
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.
- Record
GHSA-9fm9-hp7p-53mf- CVSS 4.0
- 2.3 Low
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 - Weakness
- CWE-772
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-3864- CVSS 4.0
- 2.3 Low
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-772
- Updated
- 2026-11-02
OSV
Connection pool exhaustion in hackney
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.
- Record
CVE-2025-3864- CVSS 4.0
- 2.3 Low
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 - Weakness
- CWE-772
- Updated
- 2026-11-02
OSVGHSA-9fm9-hp7p-53mf
Hackney fails to properly release HTTP connections to the pool
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.
- Record
GHSA-9fm9-hp7p-53mf- CVSS 4.0
- 2.3 Low
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 - Weakness
- CWE-772
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
hackneyHex |
before 1.24.0 | 1.24.0 |
hackneyHex |
before 1.24.0, plus listed versions 0.13.10.14.00.14.10.14.20.14.3 Show 45 moreShow less0.15.00.15.21.0.11.0.21.0.51.0.61.1.01.10.01.10.11.11.01.12.01.12.11.13.01.14.01.14.21.14.31.15.01.15.11.15.21.16.01.17.01.17.11.17.21.17.31.17.41.18.01.18.11.18.21.19.01.19.11.2.01.20.01.20.11.21.01.22.01.23.01.3.01.3.11.3.21.4.01.4.11.4.101.4.21.4.31.4.4 |
1.24.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-3864 is a low vulnerability (CVSS 2.3) in Hackney, published May 28, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.87%, the 59th percentile. Fixed in hackney 1.24.0.
References
github.com/benoitc/hackney/issues/717
cert.pl/en/posts/2025/05/CVE-2025-3864
nvd.nist.gov/vuln/detail/CVE-2025-3864
Left out here: 28 versions. The JSON record has them.