CVE-2026-4786

Description

Mitgation of CVE-2026-4519 was incomplete. If the URL contained "%action" the mitigation could be bypassed for certain browser types the "webbrowser.open()" API could have commands injected into the underlying shell. See CVE-2026-4519 for details.

References

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4786.json

https://mail.python.org/archives/list/[email protected]/thread/JQDUNJVB4AQNTJECSUKOBDU3XCJIPSE5/

https://github.com/python/cpython/pull/148170

https://github.com/python/cpython/issues/148169

https://github.com/python/cpython/commit/f4654824ae0850ac87227fb270f9057477946769

https://github.com/python/cpython/commit/d6d68494be70bdbda20f89f83801ba52ec37daa4

https://github.com/python/cpython/commit/d22922c8a7958353689dc4763dd72da2dea03fff

https://github.com/python/cpython/commit/c5767a72838a8dda9d6dc5d3558075b055c56bca

https://github.com/python/cpython/commit/28b4ad38067bbdad34edfcd03ad2de5f06387e53

https://bugzilla.redhat.com/show_bug.cgi?id=2458049

https://access.redhat.com/security/cve/CVE-2026-4786

https://access.redhat.com/errata/RHSA-2026:9228

https://access.redhat.com/errata/RHSA-2026:8824

https://access.redhat.com/errata/RHSA-2026:8822

https://access.redhat.com/errata/RHSA-2026:35838

https://access.redhat.com/errata/RHSA-2026:30089

https://access.redhat.com/errata/RHSA-2026:30088

https://access.redhat.com/errata/RHSA-2026:30087

https://access.redhat.com/errata/RHSA-2026:30078

https://access.redhat.com/errata/RHSA-2026:28581

https://access.redhat.com/errata/RHSA-2026:28247

https://access.redhat.com/errata/RHSA-2026:26187

https://access.redhat.com/errata/RHSA-2026:25096

https://access.redhat.com/errata/RHSA-2026:22144

https://access.redhat.com/errata/RHSA-2026:21682

https://access.redhat.com/errata/RHSA-2026:21275

https://access.redhat.com/errata/RHSA-2026:19590

https://access.redhat.com/errata/RHSA-2026:19589

https://access.redhat.com/errata/RHSA-2026:19576

https://access.redhat.com/errata/RHSA-2026:19571

https://access.redhat.com/errata/RHSA-2026:19570

https://access.redhat.com/errata/RHSA-2026:19549

https://access.redhat.com/errata/RHSA-2026:19216

https://access.redhat.com/errata/RHSA-2026:19177

https://access.redhat.com/errata/RHSA-2026:19176

https://access.redhat.com/errata/RHSA-2026:19175

https://access.redhat.com/errata/RHSA-2026:19064

https://access.redhat.com/errata/RHSA-2026:19019

https://access.redhat.com/errata/RHSA-2026:17619

https://access.redhat.com/errata/RHSA-2026:17525

https://access.redhat.com/errata/RHSA-2026:16699

https://access.redhat.com/errata/RHSA-2026:14656

https://access.redhat.com/errata/RHSA-2026:14653

https://access.redhat.com/errata/RHSA-2026:14652

https://access.redhat.com/errata/RHSA-2026:13812

https://access.redhat.com/errata/RHSA-2026:13692

https://access.redhat.com/errata/RHSA-2026:11768

https://access.redhat.com/errata/RHSA-2026:11077

https://access.redhat.com/errata/RHSA-2026:11062

https://access.redhat.com/errata/RHSA-2026:10950

https://access.redhat.com/errata/RHSA-2026:10949

https://access.redhat.com/errata/RHSA-2026:10774

https://access.redhat.com/errata/RHSA-2026:10745

https://access.redhat.com/errata/RHSA-2026:10711

https://access.redhat.com/errata/RHSA-2026:10141

https://access.redhat.com/errata/RHSA-2026:10140

https://access.redhat.com/errata/RHSA-2026:10117

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS