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Fencer Vulns
high 8.8

CVE-2021-41146 json

Arbitrary command execution on Windows in qutebrowser

published 2021-10-21 5 y ago modified 2026-07-08 4 mo ago also GHSA-vw27-fwjf-5qxm , PYSEC-2021-382 , EUVD-2021-0220

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

qutebrowser is an open source keyboard-focused browser with a minimal GUI. Starting with qutebrowser v1.7.0, the Windows installer for qutebrowser registers a `qutebrowserurl:` URL handler. With certain applications, opening a specially crafted `qutebrowserurl:...` URL can lead to execution of qutebrowser commands, which in turn allows arbitrary code execution via commands such as `:spawn` or `:debug-pyeval`. Only Windows installs where qutebrowser is registered as URL handler are affected. The issue has been fixed in qutebrowser v2.4.0. The fix also adds additional hardening for potential similar issues on Linux (by adding the new --untrusted-args flag to the .desktop file), though no such vulnerabilities are known.

Patch / fix

  • pypi qutebrowser 1.8.0, 2.4.0
  • qutebrowser qutebrowser 2.4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-41146 updated cvss 8.8

qutebrowser: arbitrary command execution via URL handler

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.50% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P
GitHub 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi qutebrowser
>=1.7.0, <2.4.0
<1.8.0
>=2.0.0, <2.4.0
2.4.0
1.8.0

Affected products

  • qutebrowser qutebrowser

Classification

Weakness
  • CWE-77 Improper Neutralization of Special Elements used in a Command
  • CWE-88 Improper Neutralization of Argument Delimiters in a Command
  • CWE-641 Improper Restriction of Names for Files and Other Resources

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.