CVE-2026-13346: Pip Pip Would Incorrectly Handle Doubly-encoded Vulnerability

MODERATE
Advisory Identifier: GHSA-qwm4-qh6w-59xr
Share
CWE-36
Published
Advisory Summary

CVE-2026-13346 is a MODERATE pip would incorrectly handle doubly-encoded vulnerability (CWE-36: Absolute Path Traversal) affecting Pip libraries in the PyPI ecosystem. The issue involves pip would incorrectly handle doubly-encoded package urls from indexes. Remediation is available by upgrading affected packages to version 26.2.0.

CVE-2026-13346 at a Glance

CVE Identifier CVE-2026-13346
GHSA Identifier GHSA-qwm4-qh6w-59xr
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-36: Absolute Path Traversal
Affected Product Pip
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2026-13346

To remediate this vulnerability, upgrade all affected Pip dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pip fixed: 26.2.0 
pip install pip>=26.2.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show pip

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-13346, inspect your installed packages using pip:

pip show pip

Analyze the terminal output to locate any version of Pip in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 26.2.0), your application is affected.

Note: The pip show pip command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-36: Absolute Path Traversal, where the product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as "/abs/path" that can resolve to a location that is outside of that directory. In Pip, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

pip would incorrectly handle doubly-encoded package URLs from indexes allowing for files to be installed to arbitrary locations on disk even when installing wheels. This vulnerability requires downloading or installing a package from a malicious package index to succeed, malicious packages alone are not able to exploit this vulnerability. Note that this vulnerability only materially impacts users running `pip download` with the `--only-binary` option as installing source distributions from an untrusted index is already an unsafe operation that executes code during install time.

CVE-2026-13346 Affected Pip Versions

1 component(s)
Fixed Versions:
26.2.0
Product / Package Ecosystem Affected Versions Fixed Version
pip
pypi/pip
PyPI
< 26.2.0
26.2.0

References

NVD — CVE-2026-13346 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-13346
Pip Source Repository REPOSITORY
https://github.com/pypa/pip/pull/14110
Security Fix Commit FIX COMMIT
https://github.com/pypa/pip/commit/10dfb6b9005484578b386f64b9f36982e3dc6679
Pip Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/pip/PYSEC-2026-3721.yaml
Pip Source Repository REPOSITORY
https://github.com/pypa/pip
Pip Security Information SECURITY
https://mail.python.org/archives/list/security-announce@python.org/thread/L2BNQGGVQCEV7DROOORQ7WFKKFF2OOQX
Pip Security Information SECURITY
http://www.openwall.com/lists/oss-security/2026/07/29/7

Frequently Asked Questions

What is CVE-2026-13346?
CVE-2026-13346 is a security vulnerability in Pip involving pip would incorrectly handle doubly-encoded package URLs from indexes under CWE-36: Absolute Path Traversal.
Which Pip versions are affected?
Affected versions include releases prior to 26.2.0 across affected packages: pip.
What version fixes CVE-2026-13346?
Upgrading to 26.2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pip affected?
Yes, pip is affected in releases prior to 26.2.0. Upgrade your dependency to 26.2.0 or later.
What CWE is associated with CVE-2026-13346?
CVE-2026-13346 is classified under CWE-36: Absolute Path Traversal (The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as "/abs/path" that can resolve to a location that is outside of that directory.).
How can I check PyPI dependencies for CVE-2026-13346?
Run the dependency tree command: 'pip show pip'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-qwm4-qh6w-59xr",
  "modified" : "2026-09-01T18:57:42Z",
  "published" : "2026-07-29T21:30:59Z",
  "aliases" : [ "CVE-2026-13346" ],
  "summary" : "pip would incorrectly handle doubly-encoded package URLs from indexes",
  "details" : "pip would incorrectly handle doubly-encoded package URLs from indexes allowing for files to be installed to arbitrary locations on disk even when installing wheels.\n\nThis vulnerability requires downloading or installing a package from a malicious package index to succeed, malicious packages alone are not able to exploit this vulnerability. Note that this vulnerability only materially impacts users running `pip download` with the `--only-binary` option as installing source distributions from an untrusted index is already an unsafe operation that executes code during install time.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pip"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "26.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-13346"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/pip/pull/14110"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/pip/commit/10dfb6b9005484578b386f64b9f36982e3dc6679"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/pip/PYSEC-2026-3721.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pypa/pip"
  }, {
    "type" : "WEB",
    "url" : "https://mail.python.org/archives/list/security-announce@python.org/thread/L2BNQGGVQCEV7DROOORQ7WFKKFF2OOQX"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2026/07/29/7"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-36" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-01T18:57:42Z",
    "nvd_published_at" : "2026-07-29T19:16:44Z"
  }
}