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🛡️ CVE-2025-66471 on PyPI (Root.io) — rootio-urllib3

🟠 CVSS 8.0 — High ✅ No Known Exploit OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

CVE-2025-66471 in rootio-urllib3 - Patched by Root

Root has patched CVE-2025-66471 in the rootio-urllib3 package for Root:PyPI. Multiple fixed versions available.

Distribution advisory

This page covers CVE-2025-66471 as tracked by PyPI (Root.io), for the package rootio-urllib3. The fix is available in version 1.21.1+root.io.4; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: None.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

ROOT-APP-PYPI-CVE-2025-66471 is classified as CWE-409: Improper Handling of Highly Compressed Data (Data Amplification). The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.

Affected software

ROOT-APP-PYPI-CVE-2025-66471 is recorded against 2 packages.

  • rootio-urllib3 (fixed in 1.21.1+root.io.4)
  • urllib3 (fixed in 1.21.1+aikido.4)

Timeline and source

Published on 23 June 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

Other advisories for this package

rootio-urllib3 has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)) in other software:

CVE-2025-66471 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-06-23
Updated 2026-08-20
Modified 2026-06-23
Fix URL N/A

Affected Packages

Software From version Fixed in
rootio-urllib3 — 1.21.1+root.io.4
urllib3 — 1.21.1+aikido.4

References

N/A

Site Security Check

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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