CVE-2026-4786
CVE-2026-4786 is a high-severity vulnerability with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-77.
Key facts
- Severity: High (CVSS 3.x base score 7.1)
- CVSS v4: 7.0
- EPSS exploit prediction: 0% (21st percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-22134
- Weakness: CWE-77
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-4786?
- 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.
- How severe is CVE-2026-4786?
- CVE-2026-4786 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability low.
- Is CVE-2026-4786 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-4786?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-4786 have an EU (EUVD) identifier?
- Yes. CVE-2026-4786 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22134.
- When was CVE-2026-4786 published?
- CVE-2026-4786 was published on 2026-04-13 and last updated on 2026-07-06.
References
- https://github.com/python/cpython/commit/28b4ad38067bbdad34edfcd03ad2de5f06387e53
- https://github.com/python/cpython/commit/c5767a72838a8dda9d6dc5d3558075b055c56bca
- https://github.com/python/cpython/commit/d22922c8a7958353689dc4763dd72da2dea03fff
- https://github.com/python/cpython/commit/d6d68494be70bdbda20f89f83801ba52ec37daa4
- https://github.com/python/cpython/commit/f4654824ae0850ac87227fb270f9057477946769
- https://github.com/python/cpython/issues/148169
- https://github.com/python/cpython/pull/148170
- https://mail.python.org/archives/list/[email protected]/thread/JQDUNJVB4AQNTJECSUKOBDU3XCJIPSE5/
- https://access.redhat.com/errata/RHSA-2026:10117
- https://access.redhat.com/errata/RHSA-2026:10140
- https://access.redhat.com/errata/RHSA-2026:10141
- https://access.redhat.com/errata/RHSA-2026:10711
- https://access.redhat.com/errata/RHSA-2026:10745
- https://access.redhat.com/errata/RHSA-2026:10774
- https://access.redhat.com/errata/RHSA-2026:10949
- https://access.redhat.com/errata/RHSA-2026:10950
- https://access.redhat.com/errata/RHSA-2026:11062
- https://access.redhat.com/errata/RHSA-2026:11077
- https://access.redhat.com/errata/RHSA-2026:11768
- https://access.redhat.com/errata/RHSA-2026:13692
- https://access.redhat.com/errata/RHSA-2026:13812
- https://access.redhat.com/errata/RHSA-2026:14652
- https://access.redhat.com/errata/RHSA-2026:14653
- https://access.redhat.com/errata/RHSA-2026:14656
- https://access.redhat.com/errata/RHSA-2026:16699
- https://access.redhat.com/errata/RHSA-2026:17525
- https://access.redhat.com/errata/RHSA-2026:17619
- https://access.redhat.com/errata/RHSA-2026:19019
- https://access.redhat.com/errata/RHSA-2026:19064
- https://access.redhat.com/errata/RHSA-2026:19175
Other CWE-77 (Command Injection) vulnerabilities
- CVE-2026-23652 — Critical (CVSS 10.0): Improper neutralization of special elements used in a command ('command injection') in Microsoft Power Pages allows an…
- CVE-2025-59818 — Critical (CVSS 10.0): This vulnerability allows authenticated attackers to execute arbitrary commands on the underlying system using the file…
- CVE-2025-64093 — Critical (CVSS 10.0): Remote Code Execution vulnerability that allows unauthenticated attackers to inject arbitrary commands into the…
- CVE-2025-64090 — Critical (CVSS 10.0): This vulnerability allows authenticated attackers to execute commands via the hostname of the device.
- CVE-2025-61492 — Critical (CVSS 10.0): A command injection vulnerability in the execute_command function of terminal-controller-mcp 0.1.7 allows attackers to…
- CVE-2025-10035 — Critical (CVSS 10.0): A deserialization vulnerability in the License Servlet of Fortra's GoAnywhere MFT allows an actor with a validly forged…