Bug 2458049 (CVE-2026-4786)

Summary:	CVE-2026-4786 python: cpython: Python: Arbitrary code execution via command injection in webbrowser.open() API
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	bbrownin, dfreiber, drow, jburrell, jkoehler, lphiri, sdawley, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Python webbrowser.open() API. If a specially crafted URL containing "%action" is processed, an attacker could bypass a previous mitigation for CVE-2026-4519. This bypass allows for command injection into the underlying shell, potentially leading to arbitrary code execution.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2458216, 2458217, 2458218, 2458220, 2458223, 2458219, 2458221, 2458222, 2458224, 2458225, 2458226, 2458227
Bug Blocks:

Description OSIDB Bzimport 2026-04-13 22:02:01 UTC

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.

Comment 8 errata-xmlrpc 2026-04-27 01:55:26 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

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

Comment 9 errata-xmlrpc 2026-04-27 09:38:51 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

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

Comment 10 errata-xmlrpc 2026-04-27 12:31:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

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

Comment 11 errata-xmlrpc 2026-04-27 14:42:56 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

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

Comment 12 errata-xmlrpc 2026-04-27 14:54:38 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

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

Comment 13 errata-xmlrpc 2026-04-27 20:57:55 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

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

Comment 14 errata-xmlrpc 2026-04-27 21:11:00 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

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

Comment 18 errata-xmlrpc 2026-05-05 11:12:54 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

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

Comment 19 errata-xmlrpc 2026-05-05 17:49:54 UTC

This issue has been addressed in the following products:

  RHEL-8 based Middleware Containers

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

Comment 20 errata-xmlrpc 2026-05-07 04:42:02 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

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

Comment 21 errata-xmlrpc 2026-05-07 04:45:35 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

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

Comment 22 errata-xmlrpc 2026-05-07 05:15:43 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

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

Comment 25 errata-xmlrpc 2026-05-13 01:56:54 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

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

Comment 26 errata-xmlrpc 2026-05-14 11:03:07 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

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

Comment 27 errata-xmlrpc 2026-05-14 14:50:14 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.6 Telecommunications Update Service

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

Comment 28 errata-xmlrpc 2026-05-19 13:02:36 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

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

Comment 29 errata-xmlrpc 2026-05-19 13:07:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

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

Comment 30 errata-xmlrpc 2026-05-19 17:58:58 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

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

Comment 31 errata-xmlrpc 2026-05-19 17:59:12 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

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

Comment 32 errata-xmlrpc 2026-05-19 17:59:36 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

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

Comment 33 errata-xmlrpc 2026-05-19 18:02:52 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

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

Comment 34 errata-xmlrpc 2026-05-20 08:24:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

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

Comment 35 errata-xmlrpc 2026-05-20 09:38:39 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions

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

Comment 36 errata-xmlrpc 2026-05-20 09:54:58 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

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

Comment 38 errata-xmlrpc 2026-05-20 11:04:10 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

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

Comment 40 errata-xmlrpc 2026-05-20 11:32:02 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

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

Comment 41 errata-xmlrpc 2026-05-20 11:37:22 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

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

Comment 43 errata-xmlrpc 2026-05-28 07:06:19 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Extended Update Support

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

Comment 44 errata-xmlrpc 2026-06-01 01:33:28 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6 Extended Lifecycle Support  - EXTENSION

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

Comment 46 errata-xmlrpc 2026-06-16 07:48:05 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

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