CVE-2026-4519
webbrowser.open() allows leading dashes in URLs
Description
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().
INFO
Published Date :
March 20, 2026, 3:16 p.m.
Last Modified :
April 7, 2026, 6:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 28c92f92-d60d-412d-b760-e73465c3df22 | ||||
| CVSS 4.0 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Sanitize input URLs before calling webbrowser.open().
- Update to a version that properly handles leading dashes.
- Avoid passing URLs with leading dashes.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-4519.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-4519 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-4519
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-4519 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-4519 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added Reference https://github.com/python/cpython/commit/3681d47a440865aead912a054d4599087b4270dd Added Reference https://github.com/python/cpython/commit/591ed890270c5697b013bf637029fb3e6cd2d73e Added Reference https://github.com/python/cpython/commit/594b5a05dc9913880ac92eded440defbf32a28d1 Added Reference https://github.com/python/cpython/commit/89bfb8e5ed3c7caa241028f1a4eac5f6275a46a4 Added Reference https://github.com/python/cpython/commit/96fc5048605863c7b6fd6289643feb0e97edd96c Added Reference https://github.com/python/cpython/commit/cc023511238ad93ecc8796157c6f9139a2bb2932 -
CVE Modified by [email protected]
Mar. 25, 2026
Action Type Old Value New Value Added Reference https://github.com/python/cpython/commit/cbba6119391112aba9c5aebf7b94aea447922c48 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Mar. 25, 2026
Action Type Old Value New Value Added CWE CWE-20 -
CVE Modified by [email protected]
Mar. 24, 2026
Action Type Old Value New Value Added Reference https://github.com/python/cpython/commit/43fe06b96f6a6cf5cfd5bdab20b8649374956866 Added Reference https://github.com/python/cpython/commit/82a24a4442312bdcfc4c799885e8b3e00990f02b Added Reference https://github.com/python/cpython/commit/9669a912a0e329c094e992204d6bdb8787024d76 Added Reference https://github.com/python/cpython/commit/ad4d5ba32af4d80b0dfa2ba9d8203bfb219e60a5 Added Reference https://github.com/python/cpython/commit/ceac1efc66516ac387eef2c9a0ce671895b44f03 -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Mar. 20, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/03/20/1 -
CVE Modified by [email protected]
Mar. 20, 2026
Action Type Old Value New Value Added CVSS V4.0 AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Removed CVSS V4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X -
New CVE Received by [email protected]
Mar. 20, 2026
Action Type Old Value New Value Added Description 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(). Added CVSS V4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added Reference https://github.com/python/cpython/issues/143930 Added Reference https://github.com/python/cpython/pull/143931 Added Reference https://mail.python.org/archives/list/[email protected]/thread/AY5NDSS433JK56Q7Q5IS7B37QFZVVOUS/