How severe is CVE-2025-3864?

CVE-2025-3864 has a CVSS 4.0 base score of 2.3, rated low severity.

Is CVE-2025-3864 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-3864?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-3864 have an EU (EUVD) identifier?

Yes. CVE-2025-3864 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-16328.

When was CVE-2025-3864 published?

CVE-2025-3864 was published on 2025-05-28 and last updated on 2026-06-17.

CVE-2025-3864

CVE-2025-3864 is a low-severity vulnerability with a CVSS 4.0 base score of 2.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-772.

Key facts

Severity: Low (CVSS 4.0 base score 2.3)
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-16328
Weakness: CWE-772
Published: 2025-05-28
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2025-3864?: 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.
How severe is CVE-2025-3864?: CVE-2025-3864 has a CVSS 4.0 base score of 2.3, rated low severity.
Is CVE-2025-3864 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-3864?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-3864 have an EU (EUVD) identifier?: Yes. CVE-2025-3864 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-16328.
When was CVE-2025-3864 published?: CVE-2025-3864 was published on 2025-05-28 and last updated on 2026-06-17.

References

Other CWE-772 vulnerabilities

CVE-2020-12134 — Critical (CVSS 9.8): Nanometrics Centaur through 4.3.23 and TitanSMA through 4.2.20 mishandle access control for the syslog log.
CVE-2017-15032 — Critical (CVSS 9.8): ImageMagick version 7.0.7-2 contains a memory leak in ReadYCBCRImage in coders/ycbcr.c.
CVE-2017-14138 — Critical (CVSS 9.8): ImageMagick 7.0.6-5 has a memory leak vulnerability in ReadWEBPImage in coders/webp.c because memory is not freed in…
CVE-2017-11641 — Critical (CVSS 9.8): GraphicsMagick 1.3.26 has a Memory Leak in the PersistCache function in magick/pixel_cache.c during writing of Magick…
CVE-2020-14339 — High (CVSS 8.8): A flaw was found in libvirt, where it leaked a file descriptor for `/dev/mapper/control` into the QEMU process. This…
CVE-2018-19760 — High (CVSS 8.8): cfg_init in confuse.c in libConfuse 3.2.2 has a memory leak.

Browse all CWE-772 vulnerabilities →