CVE-2026-4519

low-risk
Published 2026-03-20

The webbrowser.open() API would accept leading dashes in the URL which could be handled as command line options for certain web browsers. New behavior rejects leading dashes. Users are recommended to sanitize URLs prior to passing to webbrowser.open().

Do I need to act?

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0.01% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
3
CVSS 3.3/10 Low
LOCAL / LOW complexity

Affected Products (8)

Affected Vendors

Python

References (16)

Patch https://github.com/python/cpython/commit/3681d47a440865aead912a054d4599087b4270d...
Patch https://github.com/python/cpython/commit/43fe06b96f6a6cf5cfd5bdab20b864937495686...
Patch https://github.com/python/cpython/commit/591ed890270c5697b013bf637029fb3e6cd2d73...
Patch https://github.com/python/cpython/commit/594b5a05dc9913880ac92eded440defbf32a28d...
Patch https://github.com/python/cpython/commit/82a24a4442312bdcfc4c799885e8b3e00990f02...
Patch https://github.com/python/cpython/commit/89bfb8e5ed3c7caa241028f1a4eac5f6275a46a...
Patch https://github.com/python/cpython/commit/9669a912a0e329c094e992204d6bdb8787024d7...
Patch https://github.com/python/cpython/commit/96fc5048605863c7b6fd6289643feb0e97edd96...
Patch https://github.com/python/cpython/commit/ad4d5ba32af4d80b0dfa2ba9d8203bfb219e60a...
Patch https://github.com/python/cpython/commit/cbba6119391112aba9c5aebf7b94aea447922c4...
Patch https://github.com/python/cpython/commit/cc023511238ad93ecc8796157c6f9139a2bb293...
Patch https://github.com/python/cpython/commit/ceac1efc66516ac387eef2c9a0ce671895b44f0...
Issue Tracking https://github.com/python/cpython/issues/143930
Issue Tracking https://github.com/python/cpython/pull/143931
Vendor Advisory https://mail.python.org/archives/list/security-announce@python.org/thread/AY5NDS...
Mailing List http://www.openwall.com/lists/oss-security/2026/03/20/1
27
/ 100
low-risk
Severity 13/34 · Low
Exploitability 0/34 · Minimal
Exposure 14/34 · Moderate