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Full vulnerability report · 2026
CVE-2026-4786High confidence

Incomplete mitigation of CVE-2026-4519, %action expansion for command injection to webbrowser.open()

Python Software Foundation · CPython

7.0HighCVSS 4.0
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

3 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivejythonUnder evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivepypy3Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivepython3.12Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.3.12.3-1ubuntu0.15Canonical record ↗Source updated 8 Sept 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-22134

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

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.

What

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.

Why

Untrusted input reaches a command interpreter without sufficient validation or separation from command syntax.

How

An attacker operating through local access may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

Untrusted input reaches a command interpreter without sufficient validation or separation from command syntax.

How

An attacker operating through local access may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Improper Neutralization of Special Elements used in a Command ('Command Injection') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
None: unauthenticated exploitation is possible
User interaction
Active interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-77

CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection'). The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIActiveUser interaction: A user must take a deliberate action for exploitation to succeed.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
UnauthenticatedCWE-77
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2026-2455Oracle Solaris Drittanbieterkomponenten: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in verschiedenen Komponenten von Drittanbietern in Oracle Solaris ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

Official advisory
BSI · German · WID-SEC-W-2026-1666IBM QRadar SIEM: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM QRadar SIEM ausnutzen, um beliebigen Programmcode auszuführen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, und um Sicherheitsvorkehrungen zu umgehen.

Official advisory
BSI · German · WID-SEC-W-2026-1087CPython: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Python ausnutzen, um Sicherheitsvorkehrungen zu umgehen, und um Daten zu manipulieren.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0958Multiples vulnérabilités dans les produits IBM

ord?id=CVE-2026-44496 Référence CVE CVE-2026-44930 https://www.cve.org/CVERecord?id=CVE-2026-44930 Référence CVE CVE-2026-4519 https://www.cve.org/CVERecord?id=CVE-2026-4519 Référence CVE CVE-2026-45292 https://www.cve.org/CVERecord?id=CVE-2026-45292 Référence CVE CVE-2026-45505 https://www.cve.org/CVERecord?id=CVE-2026-45505 Référence CVE CVE-2026-46595 https://www.cve.org/CVERecord?id=CVE-2026-46595 Référence CVE CVE-2026-46597 https://www.cve.org/CVERecord?id=CVE-2026-46597 Référence CVE CVE-2026-46598 https://www.cve.org/CVERecord?id=CVE-2026-46598 Référence CVE CVE-2026-46605 https://www.cve.org/CVERecord?id=CVE-2026-46605 Référence CVE CVE-2026-4786 https://www.cve.org/CVERecord?id=CVE-2026-4786 Référence CVE CVE-2026-4800 https://www.cve.org/CVERecord?id=CVE-2026-4800 Référence CVE CVE-2026-4867 https://www.cve.org/CVERecord?id=CVE-2026-4867 Référence CVE CVE-2026-49157 https://www.cve.org/CVERecord?id=CVE-2026-49157 Référence CVE CVE-2026-49270 https://www.cve.org/CVERecord?id=CVE-2026-49270 Référence CVE CVE-2026-49844 https://www.cve.org/CVERecord?id=CVE-2026-49844 Référence CVE CVE-2026-5038 https://www.cve.org/CVERecord?id=CVE-2026-5038 Référence CVE CVE-2026-5079 https://www.cve.org/CVERecord?id=CVE-2026-5079 Référence CVE CVE-2026-53550 https://www.cve.org/CVERecord?id=CVE-2026-

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0667Multiples vulnérabilités dans les produits IBM

ecord?id=CVE-2026-40466 Référence CVE CVE-2026-40973 https://www.cve.org/CVERecord?id=CVE-2026-40973 Référence CVE CVE-2026-40974 https://www.cve.org/CVERecord?id=CVE-2026-40974 Référence CVE CVE-2026-40975 https://www.cve.org/CVERecord?id=CVE-2026-40975 Référence CVE CVE-2026-40977 https://www.cve.org/CVERecord?id=CVE-2026-40977 Référence CVE CVE-2026-41044 https://www.cve.org/CVERecord?id=CVE-2026-41044 Référence CVE CVE-2026-41324 https://www.cve.org/CVERecord?id=CVE-2026-41324 Référence CVE CVE-2026-4424 https://www.cve.org/CVERecord?id=CVE-2026-4424 Référence CVE CVE-2026-4519 https://www.cve.org/CVERecord?id=CVE-2026-4519 Référence CVE CVE-2026-4786 https://www.cve.org/CVERecord?id=CVE-2026-4786 Référence CVE CVE-2026-4800 https://www.cve.org/CVERecord?id=CVE-2026-4800 Référence CVE CVE-2026-4867 https://www.cve.org/CVERecord?id=CVE-2026-4867 Référence CVE CVE-2026-4923 https://www.cve.org/CVERecord?id=CVE-2026-4923 Référence CVE CVE-2026-4926 https://www.cve.org/CVERecord?id=CVE-2026-4926 Référence CVE CVE-2026-5121 https://www.cve.org/CVERecord?id=CVE-2026-5121 Référence CVE CVE-2026-5598 https://www.cve.org/CVERecord?id=CVE-2026-5598 Référence CVE CVE-2026-5795 https://www.cve.org/CVERecord?id=CVE-2026-5795 Référence CVE CVE-2026-6100 https://www.cve.org/CVERecord?id=CVE-2026-6100 Ré

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0556Multiples vulnérabilités dans les produits VMware

g/CVERecord?id=CVE-2026-39883 Référence CVE CVE-2026-39892 https://www.cve.org/CVERecord?id=CVE-2026-39892 Référence CVE CVE-2026-40192 https://www.cve.org/CVERecord?id=CVE-2026-40192 Référence CVE CVE-2026-41066 https://www.cve.org/CVERecord?id=CVE-2026-41066 Référence CVE CVE-2026-4111 https://www.cve.org/CVERecord?id=CVE-2026-4111 Référence CVE CVE-2026-4224 https://www.cve.org/CVERecord?id=CVE-2026-4224 Référence CVE CVE-2026-4424 https://www.cve.org/CVERecord?id=CVE-2026-4424 Référence CVE CVE-2026-4519 https://www.cve.org/CVERecord?id=CVE-2026-4519 Référence CVE CVE-2026-4539 https://www.cve.org/CVERecord?id=CVE-2026-4539 Référence CVE CVE-2026-4786 https://www.cve.org/CVERecord?id=CVE-2026-4786 Référence CVE CVE-2026-4878 https://www.cve.org/CVERecord?id=CVE-2026-4878 Référence CVE CVE-2026-5121 https://www.cve.org/CVERecord?id=CVE-2026-5121 Référence CVE CVE-2026-5598 https://www.cve.org/CVERecord?id=CVE-2026-5598 Référence CVE CVE-2026-6100 https://www.cve.org/CVERecord?id=CVE-2026-6100 Gestion détaillée du document le 11 mai 2026 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propos Contact cyber.gouv.fr service-public.fr legifrance.gouv.fr info.gouv.fr france.fr info.gouv.fr/risques Premier Ministre / Secrétariat Général de la Défense e

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0430Multiples vulnérabilités dans Python

De multiples vulnérabilités ont été découvertes dans Python. Elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance et un problème de sécurité non spécifié par l'éditeur.

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
< 3.10.21; 3.11.0 < 3.11.16; 3.12.0 < 3.12.14; 3.13.0 < 3.13.14; 3.14.0a1 < 3.14.5rc1; 3.15.0a1 < 3.15.0b1
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 13 Apr 2026 · Last source change 13 Aug 2026, 00:27 UTC · CWE-77 · Improper Neutralization of Special Elements used in a Command ('Command Injection')

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-22134
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-4786 · cve.blacktree.nl