7.1

CVE-2026-4519: webbrowser.open() allows leading dashes in URLs

Modified
AliasesALPINE-CVE-2026-4519RHSA-2026:10101RHSA-2026:10102
Published 20-03-2026Last modified 13-08-2026

Vulnerability summary

CVE-2026-4519 is a high (CVSS 7.1) Improper Input Validation vulnerability in python software foundation cpython. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 24.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.31%
0%100%
Low · -0.08 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 32 · Related 24

Timeline

  1. 20-03-2026
    PublishedVulnerability first disclosed.
  2. 13-08-2026
    Last modifiedVulnerability information updated.

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().

CVSS metrics

11 scores · 8 sources · 2 versions

EPSS trend

Probability

0.31%

Chance of exploitation in the next 30 days

Percentile

24%

Versus all other CVEs

30-day change

Decrease -0.08 pp

From 0.39% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Redhat44 products
  • platform-python< 0:3.6.8-75.el8_10 | < 0:3.6.8-51.el8_8.14 | < 0:3.6.8-47.el8_6.12 | < 0:3.6.8-24.el8_2.7 | < 0:3.6.8-39.el8_4.10
  • platform-python-debug< 0:3.6.8-75.el8_10 | < 0:3.6.8-51.el8_8.14 | < 0:3.6.8-47.el8_6.12 | < 0:3.6.8-24.el8_2.7 | < 0:3.6.8-39.el8_4.10
  • platform-python-devel< 0:3.6.8-75.el8_10 | < 0:3.6.8-51.el8_8.14 | < 0:3.6.8-47.el8_6.12 | < 0:3.6.8-24.el8_2.7 | < 0:3.6.8-39.el8_4.10
  • python< 0:2.6.6-70.el6_10.3 | < 0:2.7.5-94.el7_9.4
  • python-debug< 0:2.7.5-94.el7_9.4
Ubuntu14 products
  • jythonAll versions (No fix recorded)
  • pypy3All versions (No fix recorded)
  • python2.7All versions (No fix recorded)
  • python3.10< 3.10.12-1~22.04.16
  • python3.11All versions (No fix recorded)
Chainguard6 products
  • python-3.10< 3.10.20-r1
  • python-3.11< 3.11.15-r1
  • python-3.12< 3.12.13-r1
  • python-3.13< 3.13.12-r5
  • python-3.14< 3.14.3-r5
Debian5 products
  • jythonAll versions (No fix recorded)
  • pypy3All versions (No fix recorded) | < 7.3.22+dfsg-1
  • python3.11< 3.11.2-6+deb12u8
  • python3.13< 3.13.14-1 | < 3.13.5-2+deb13u2
  • python3.14< 3.14.4-1
Wolfi5 products
  • python-3.10< 3.10.20-r1
  • python-3.11< 3.11.15-r1
  • python-3.12< 3.12.13-r1
  • python-3.13< 3.13.12-r5
  • python-3.14< 3.14.3-r5
Alpine1 product
  • python3< 3.12.14-r0
Python1 product
  • python< 3.13.13 | ≥ 3.14.0, < 3.14.4 | 3.15.0:alpha1 | 3.15.0:alpha2 | 3.15.0:alpha3 | 3.15.0:alpha4 | 3.15.0:alpha5 | 3.15.0:alpha6 | 3.15.0:alpha7
Python software foundation1 product
  • cpython< 3.10.21 | ≥ 3.11.0, < 3.11.16 | ≥ 3.12.0, < 3.12.14 | ≥ 3.13.0, < 3.13.13 | ≥ 3.14.0, < 3.14.4 | ≥ 3.15.0a1, < 3.15.0a8

8 vendors · 77 products

References

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