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.

CVSS 4.0

7.0CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

7.1CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L

EPSS

0.3% chance of exploitation in the next 30 days; higher than 21% of CVEs (scores of 2026-10-26)

CWEs

CWE-77, CWE-88

Published

2026-04-13

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

References

• https://github.com/python/cpython/commit/28b4ad38067bbdad34edfcd03ad2de5f06387e53
• https://github.com/python/cpython/commit/a4d3edf3a6ecfde504d02126410d2a65a859b744
• https://github.com/python/cpython/commit/c5767a72838a8dda9d6dc5d3558075b055c56bca
• https://github.com/python/cpython/commit/d22922c8a7958353689dc4763dd72da2dea03fff
• https://github.com/python/cpython/commit/d6d68494be70bdbda20f89f83801ba52ec37daa4

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