CVE-2025-3864 json
Connection pool exhaustion in hackney
published last yr. modified 4mo ago also GHSA-9fm9-hp7p-53mf , EUVD-2025-16328
- cvss
- 2.3
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 59%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Is CVE-2025-3864 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- last yr.
Exploit prediction
0.87% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 2.3 | 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 |
| CNA | 4.0 | 2.3 | 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 |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| hex | hackney | <1.24.0 |
1.24.0 |
Affected products
- hackney hackney
Classification
- Weakness
-
- CWE-772 Missing Release of Resource after Effective Lifetime
References
-
github.com
/benoitc/hackney/commit/8f13ddac50d1626f8b9a47a08bd599e4efe1773d
patch, web
-
github.com
/benoitc/hackney/issues/717
issue-tracking, web
-
cert.pl
/en/posts/2025/05/CVE-2025-3864/
third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2025-3864
advisory
-
cert.pl
/en/posts/2025/05/CVE-2025-3864
web
-
github.com
/benoitc/hackney
package
Sources
- CVE List CVE-2025-3864
- GitHub Advisory GHSA-9fm9-hp7p-53mf
- NVD CVE-2025-3864
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