CVE-2025-3864 (GCVE-0-2025-3864)
Vulnerability from cvelistv5 – Published: 2025-05-28 11:19 – Updated: 2026-01-26 12:13 X_Open Source
VLAI
EPSS
VEX
Title
Connection pool exhaustion in hackney
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.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-05-28 13:17 UTC
CWE
- CWE-772 - Missing Release of Resource after Effective Lifetime
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/benoitc/hackney/issues/717 | issue-tracking |
| https://cert.pl/en/posts/2025/05/CVE-2025-3864/ | third-party-advisory |
| https://github.com/benoitc/hackney/commit/8f13dda… | patch |
Impacted products
Date Public
2025-05-27 10:05
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2025-3864",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-05-28T13:17:43.365984Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2025-05-28T13:17:57.950Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unknown",
"product": "hackney",
"repo": "https://github.com/benoitc/hackney",
"vendor": "hackney",
"versions": [
{
"lessThan": "1.24.0",
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Micha\u0142 Majchrowicz, Marcin Wyczechowski, and Pawe\u0142 Zdunek \u2014 members of the AFINE Team"
}
],
"datePublic": "2025-05-27T10:05:00.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "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.\u003cbr\u003eFix for this issue has been included in\u0026nbsp;1.24.0 release."
}
],
"value": "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.\nFix for this issue has been included in\u00a01.24.0 release."
}
],
"impacts": [
{
"capecId": "CAPEC-469",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-469 HTTP DoS"
}
]
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"baseScore": 2.3,
"baseSeverity": "LOW",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "PASSIVE",
"valueDensity": "NOT_DEFINED",
"vectorString": "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",
"version": "4.0",
"vulnAvailabilityImpact": "LOW",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-772",
"description": "CWE-772 Missing Release of Resource after Effective Lifetime",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-01-26T12:13:02.411Z",
"orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
"shortName": "CERT-PL"
},
"references": [
{
"tags": [
"issue-tracking"
],
"url": "https://github.com/benoitc/hackney/issues/717"
},
{
"tags": [
"third-party-advisory"
],
"url": "https://cert.pl/en/posts/2025/05/CVE-2025-3864/"
},
{
"tags": [
"patch"
],
"url": "https://github.com/benoitc/hackney/commit/8f13ddac50d1626f8b9a47a08bd599e4efe1773d"
}
],
"source": {
"discovery": "EXTERNAL"
},
"tags": [
"x_open-source"
],
"title": "Connection pool exhaustion in hackney",
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
"assignerShortName": "CERT-PL",
"cveId": "CVE-2025-3864",
"datePublished": "2025-05-28T11:19:15.208Z",
"dateReserved": "2025-04-22T08:43:49.641Z",
"dateUpdated": "2026-01-26T12:13:02.411Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2025-3864",
"date": "2026-10-28",
"epss": "0.00871",
"percentile": "0.58696"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unknown",
"product": "hackney",
"repo": "https://github.com/benoitc/hackney",
"vendor": "hackney",
"versions": [
{
"lessThan": "1.24.0",
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"source": "cvd@cert.pl"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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.\nFix for this issue has been included in\u00a01.24.0 release."
},
{
"lang": "es",
"value": "Hackney no libera correctamente las conexiones HTTP al pool tras gestionar respuestas de redirecci\u00f3n temporal 307. Atacantes remotos pueden aprovechar esto para agotar los pools de conexiones, lo que provoca una denegaci\u00f3n de servicio en las aplicaciones que usan la librer\u00eda. Se ha incluido una soluci\u00f3n para este problema en la versi\u00f3n 1.24.0."
}
],
"id": "CVE-2025-3864",
"lastModified": "2026-06-17T09:20:49.693",
"metrics": {
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 2.3,
"baseSeverity": "LOW",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "PASSIVE",
"valueDensity": "NOT_DEFINED",
"vectorString": "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",
"version": "4.0",
"vulnAvailabilityImpact": "LOW",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "cvd@cert.pl",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2025-3864",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-05-28T13:17:43.365984Z",
"version": "2.0.3"
}
}
]
},
"published": "2025-05-28T12:15:19.760",
"references": [
{
"source": "cvd@cert.pl",
"url": "https://cert.pl/en/posts/2025/05/CVE-2025-3864/"
},
{
"source": "cvd@cert.pl",
"url": "https://github.com/benoitc/hackney/commit/8f13ddac50d1626f8b9a47a08bd599e4efe1773d"
},
{
"source": "cvd@cert.pl",
"url": "https://github.com/benoitc/hackney/issues/717"
}
],
"sourceIdentifier": "cvd@cert.pl",
"vulnStatus": "Deferred",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-772"
}
],
"source": "cvd@cert.pl",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"current_release_date": "2026-01-26T15:10:22+00:00",
"cve": "CVE-2025-3864",
"id": "CVE-2025-3864",
"initial_release_date": "2025-05-27T10:05:00+00:00",
"product_status:known_not_affected": "1",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "Connection pool exhaustion in hackney",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-3864.json",
"version": "3"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2025-3864",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-05-28T13:17:43.365984Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2025-05-28T13:17:51.796Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unknown",
"product": "hackney",
"repo": "https://github.com/benoitc/hackney",
"vendor": "hackney",
"versions": [
{
"lessThan": "1.24.0",
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "Micha\u0142 Majchrowicz, Marcin Wyczechowski, and Pawe\u0142 Zdunek \u2014 members of the AFINE Team"
}
],
"datePublic": "2025-05-27T10:05:00.000Z",
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "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.\u003cbr\u003eFix for this issue has been included in\u0026nbsp;1.24.0 release."
}
],
"value": "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.\nFix for this issue has been included in\u00a01.24.0 release."
}
],
"impacts": [
{
"capecId": "CAPEC-469",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-469 HTTP DoS"
}
]
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"attackVector": "NETWORK",
"baseScore": 2.3,
"baseSeverity": "LOW",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "PASSIVE",
"valueDensity": "NOT_DEFINED",
"vectorString": "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",
"version": "4.0",
"vulnAvailabilityImpact": "LOW",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-772",
"description": "CWE-772 Missing Release of Resource after Effective Lifetime",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-01-26T12:13:02.411Z",
"orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
"shortName": "CERT-PL"
},
"references": [
{
"tags": [
"issue-tracking"
],
"url": "https://github.com/benoitc/hackney/issues/717"
},
{
"tags": [
"third-party-advisory"
],
"url": "https://cert.pl/en/posts/2025/05/CVE-2025-3864/"
},
{
"tags": [
"patch"
],
"url": "https://github.com/benoitc/hackney/commit/8f13ddac50d1626f8b9a47a08bd599e4efe1773d"
}
],
"source": {
"discovery": "EXTERNAL"
},
"tags": [
"x_open-source"
],
"title": "Connection pool exhaustion in hackney",
"x_generator": {
"engine": "Vulnogram 0.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
"assignerShortName": "CERT-PL",
"cveId": "CVE-2025-3864",
"datePublished": "2025-05-28T11:19:15.208Z",
"dateReserved": "2025-04-22T08:43:49.641Z",
"dateUpdated": "2026-01-26T12:13:02.411Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.