CVE-2025-8869Network attack vector

Arbitrary file write via unchecked archive symlinks

Published Sep 24, 2025 · Updated Sep 24, 2025

Path traversal in Python Packaging Authority pip before 25.3 allows attackers to write outside its extraction directory via a crafted archive. When PEP 706 support is unavailable, _untar_without_filter passes archive symlinks to tar._extract_member without first ensuring that each target remains inside the archive. Exploitation requires installation of a malicious source distribution and writes with the privileges of the pip process.

CVSS severity5.9
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Python Packaging Authority pip before 25.3 allows attackers to write outside its extraction directory via a crafted archive. When PEP 706 support is unavailable, _untar_without_filter passes archive symlinks to tar._extract_member without first ensuring that each target remains inside the archive. Exploitation requires installation of a malicious source distribution and writes with the privileges of the pip process.

The record

CVE
CVE-2025-8869
Published
Sep 24, 2025
Updated
Sep 24, 2025
Vendor
Python Packaging Authority
Product
pip
Classifications
CWE-59, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 24, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 24, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <25.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Python Packaging Authority · pipversion=0 <25.3

Published CVSS scores

5.9Python Software FoundationCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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