CVE-2026-4786: Python Software Foundation CPython · Command Injection
Affects Python Software Foundation CPythonSource CVE Database V5
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.0 High · fixed in 3.15.0b1 : patch Python Software Foundation CPython soon.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.15.0b1, 3.14.5rc1, 3.13.14 +3
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Python Software FoundationCPython | Affected
| Fixed in
|
| Python Software FoundationCPython | Affected
| Fixed in
|
| Python Software FoundationCPython | Affected
| Fixed in
|
| Python Software FoundationCPython | Affected
| Fixed in
|
| Python Software FoundationCPython | Affected
| Fixed in
|
| Python Software FoundationCPython | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released security updates addressing CVE-2026-4786 for their supported products, including Red Hat Enterprise Linux Server Extended Lifecycle Support Extension 6. Users should apply these updates as soon as possible. Currently, no universal mitigation is available or meets Red Hat's criteria for ease of use and deployment. For Red Hat customers, consulting with a Technical Account Manager (TAM) is recommended for tailored guidance. No additional mitigations are specified beyond applying the vendor-provided updates.
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
- github.com/python/cpython/pull/148170 (opens in a new tab)
- github.com/python/cpython/issues/148169 (opens in a new tab)
- mail.python.org/archives/list/security-announce@python.org/thread/JQDUNJVB4AQNTJECSUKOBDU3XCJIPSE5/ (opens in a new tab)
- github.com/python/cpython/commit/c5767a72838a8dda9d6dc5d3558075b055c56bca (opens in a new tab)
- github.com/python/cpython/commit/d22922c8a7958353689dc4763dd72da2dea03fff (opens in a new tab)
- github.com/python/cpython/commit/f4654824ae0850ac87227fb270f9057477946769 (opens in a new tab)
- github.com/python/cpython/commit/28b4ad38067bbdad34edfcd03ad2de5f06387e53 (opens in a new tab)
- github.com/python/cpython/commit/d6d68494be70bdbda20f89f83801ba52ec37daa4 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-4786 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2458049 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4786.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:22144 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19589 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:35838 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:13812 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:16699 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10711 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19064 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19019 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:28581 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:11077 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:11062 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10950 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19590 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17619 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19549 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26187 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19571 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19570 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:13692 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:21682 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:14653 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:17525 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19576 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:14652 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:14656 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10949 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10774 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10745 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19216 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19175 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19177 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19176 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:28247 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:25096 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:30078 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:30089 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:30088 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:30087 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10140 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10141 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:8822 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:8824 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:10117 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:9228 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:11768 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:21275 (opens in a new tab)
- github.com/python/cpython/commit/a4d3edf3a6ecfde504d02126410d2a65a859b744 (opens in a new tab)