CVE-2025-66471

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 96% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.0 and prior to 2.6.0, the Streaming API improperly handles highly compressed data. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. When streaming a compressed response, urllib3 can perform decoding or decompression based on the HTTP Content-Encoding header (e.g., gzip, deflate, br, or zstd). The library must read compressed data from the network and decompress it until the requested chunk size is met. Any resulting decompressed data that exceeds the requested amount is held in an internal buffer for the next read operation. The decompression logic could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This can result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
46.2%
KEV
Not listed

Published

December 5, 2025

Last Modified

June 17, 2026

References (2)

Vendor Advisories for CVE-2025-66471(20)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(30)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhoai/odh-vllm-cpu-rhel9:17782643632026-05-20redhat
redhatsatellite/iop-puptoo-rhel9:17767968292026-05-07redhat
redhatpython-urllib3-0:1.10.2-3.el6_10.12026-04-29redhat
redhatrhoai/odh-vllm-cpu-rhel9:17762590632026-04-23redhat
redhatpython-urllib3-0:1.10.2-7.el7_9.12026-04-20redhat
redhatsatellite/iop-insights-engine-rhel9:17738379612026-03-31redhat
redhatopenshift-builds/openshift-builds-shared-resource-rhel9:17739315902026-03-30redhat
redhatopenshift-builds/openshift-builds-shared-resource-rhel9:17739319942026-03-24redhat
redhatrhtas/tuffer-rhel9:17733073092026-03-23redhat
redhatadvanced-cluster-security/rhacs-scanner-v4-db-rhel8:17732358802026-03-12redhat
redhatadvanced-cluster-security/rhacs-collector-rhel8:17714013142026-03-12redhat
redhatrhtas/model-transparency-rhel9:17726146352026-03-11redhat
redhatquay/quay-rhel8:17730976212026-03-10redhat
redhatquay/quay-rhel8:17730888622026-03-10redhat
redhatansible-automation-platform-26/hub-rhel9-operator:17723823252026-03-06redhat
redhatopenshift-gitops-1/console-plugin-rhel8:17721959952026-03-05redhat
redhatopenshift-gitops-1/console-plugin-rhel8:17724388222026-03-05redhat
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17718741812026-03-04redhat
redhatrhoai/odh-vllm-gaudi-rhel9:17720932782026-03-04redhat
redhatrhaiis/vllm-cuda-rhel9:17721605932026-02-27redhat
redhatrhaiis/vllm-rocm-rhel9:17721606252026-02-27redhat
redhatrhceph/rhceph-9-rhel9:17718160282026-02-26redhat
redhatoadp/oadp-velero-rhel9:17704210822026-02-26redhat
redhatrhtas/policy-controller-rhel9-operator:17719317082026-02-25redhat
redhatrhtas/segment-reporting-rhel9:17707390202026-02-18redhat
redhatrhtas/client-server-rhel9:17707897922026-02-18redhat
redhatrhtas/trillian-redis-rhel9:17707341182026-02-18redhat
redhatrhtas/tuftool-rhel9:17707368362026-02-18redhat
redhatnetwork-observability/network-observability-cli-rhel9:17712260602026-02-18redhat
redhatrhceph/rhceph-7-rhel9:17706327242026-02-17redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
urllib31.0 ... 2.5.0 (98 versions)2.6.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(22)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 9× in last 7d / 47× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-15 16:57 UTCEPSS rescore
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 01:59 UTCEPSS rescore
  4. 2026-07-15 01:59 UTCEPSS rescore
  5. 2026-07-13 22:29 UTCEPSS rescore
  6. 2026-07-13 06:12 UTCEPSS rescore
  7. 2026-07-12 05:46 UTCEPSS rescore
  8. 2026-07-11 08:27 UTCEPSS rescore
  9. 2026-07-09 19:09 UTCEPSS rescore
  10. 2026-07-08 15:15 UTCEPSS rescore
  11. 2026-07-07 13:46 UTCEPSS rescore
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 08:41 UTCOSV refresh
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-06 02:23 UTCEPSS rescore
  17. 2026-07-05 02:30 UTCEPSS rescore
  18. 2026-07-05 02:30 UTCEPSS rescore
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-07-04 06:30 UTCEPSS rescore
  21. 2026-07-01 15:06 UTCEPSS rescore
  22. 2026-07-01 15:06 UTCEPSS rescore
  23. 2026-06-30 23:22 UTCEPSS rescore
  24. 2026-06-29 14:06 UTCEPSS rescore
  25. 2026-06-29 14:06 UTCEPSS rescore
Show 55 more
  1. 2026-06-28 14:07 UTCEPSS rescore
  2. 2026-06-28 14:07 UTCEPSS rescore
  3. 2026-06-28 04:56 UTCEPSS rescore
  4. 2026-06-28 04:55 UTCEPSS rescore
  5. 2026-06-27 03:08 UTCEPSS rescore
  6. 2026-06-25 13:49 UTCEPSS rescore
  7. 2026-06-24 14:04 UTCEPSS rescore
  8. 2026-06-24 14:04 UTCEPSS rescore
  9. 2026-06-23 21:32 UTCEPSS rescore
  10. 2026-06-23 21:32 UTCEPSS rescore
  11. 2026-06-22 14:25 UTCEPSS rescore
  12. 2026-06-21 14:56 UTCEPSS rescore
  13. 2026-06-21 14:56 UTCEPSS rescore
  14. 2026-06-21 01:59 UTCEPSS rescore
  15. 2026-06-21 01:59 UTCEPSS rescore
  16. 2026-06-19 19:25 UTCEPSS rescore
  17. 2026-06-19 19:25 UTCEPSS rescore
  18. 2026-06-18 17:52 UTCEPSS rescore
  19. 2026-06-18 17:52 UTCEPSS rescore
  20. 2026-06-17 20:35 UTCOSV refresh
  21. 2026-06-17 17:52 UTCEPSS rescore
  22. 2026-06-16 17:52 UTCEPSS rescore
  23. 2026-06-15 17:48 UTCEPSS rescore
  24. 2026-06-15 17:48 UTCEPSS rescore
  25. 2026-06-14 23:18 UTCEPSS rescore
  26. 2026-06-13 23:00 UTCEPSS rescore
  27. 2026-06-13 23:00 UTCEPSS rescore
  28. 2026-06-12 23:11 UTCEPSS rescore
  29. 2026-06-11 14:00 UTCEPSS rescore
  30. 2026-06-10 22:18 UTCEPSS rescore
  31. 2026-06-10 22:18 UTCEPSS rescore
  32. 2026-06-10 13:22 UTCEPSS rescore
  33. 2026-06-08 14:17 UTCEPSS rescore
  34. 2026-06-08 14:16 UTCEPSS rescore
  35. 2026-06-07 15:24 UTCEPSS rescore
  36. 2026-06-07 15:24 UTCEPSS rescore
  37. 2026-06-06 13:47 UTCEPSS rescore
  38. 2026-06-06 13:47 UTCEPSS rescore
  39. 2026-06-05 22:46 UTCEPSS rescore
  40. 2026-06-05 22:46 UTCEPSS rescore
  41. 2026-06-05 06:10 UTCEPSS rescore
  42. 2026-06-05 06:10 UTCEPSS rescore
  43. 2026-06-04 13:12 UTCEPSS rescore
  44. 2026-06-04 13:12 UTCEPSS rescore
  45. 2026-06-02 20:13 UTCEPSS rescore
  46. 2026-06-02 20:12 UTCEPSS rescore
  47. 2026-06-01 13:51 UTCEPSS rescore
  48. 2026-06-01 13:51 UTCEPSS rescore
  49. 2026-05-31 22:30 UTCEPSS rescore
  50. 2026-05-31 22:30 UTCEPSS rescore
  51. 2026-05-31 00:16 UTCEPSS rescore
  52. 2026-05-31 00:16 UTCEPSS rescore
  53. 2026-05-29 18:21 UTCEG score recompute
  54. 2026-05-29 18:21 UTCVendor advisory
  55. 2026-05-29 13:44 UTCEPSS rescore

Frequently asked(5)

What is CVE-2025-66471?
CVE-2025-66471 is a high vulnerability published on December 5, 2025. urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.0 and prior to 2.6.0, the Streaming API improperly handles highly compressed data. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than…
When was CVE-2025-66471 disclosed?
CVE-2025-66471 was first published in the National Vulnerability Database on December 5, 2025, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-66471 actively exploited?
CVE-2025-66471 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 46.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-66471?
CVE-2025-66471 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2025-66471?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-66471, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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