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Fencer Vulns
medium 5.4

CVE-2016-2817 json

The WebExtension sandbox feature in browser/components/extensions/ext-tabs.js in Mozilla Firefox before 46.0 does not properly restrict pri…

published 2016-04-30 10 y ago modified 2026-06-17 4 mo ago also EUVD-2016-3890

cvss
5.4
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 69%
public exploits
0
none known

Summary

The WebExtension sandbox feature in browser/components/extensions/ext-tabs.js in Mozilla Firefox before 46.0 does not properly restrict principal inheritance during chrome.tabs.create and chrome.tabs.update API calls, which allows remote attackers to conduct Universal XSS (UXSS) attacks via a crafted extension that accesses a (1) javascript: or (2) data: URL.

Patch / fix

  • firefox Ubuntu 14.04 LTS 46.0+build5-0ubuntu0.14.04.2
  • firefox Ubuntu 16.04 LTS 46.0+build5-0ubuntu0.16.04.2

ubuntu advisories UBUNTU-CVE-2016-2817

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 50.1.0-1.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10071-1

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-2016-2817 updated cvss 4.3

Mozilla: Elevation of privilege with chrome.tabs.update API in web extensions (MFSA 2016-46)

  • Red Hat Enterprise Linux 5 firefox Red Hat Enterprise Linux 6 firefox Red Hat Enterprise Linux 7 firefox
    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

1.25% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 5.4 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-264 Permissions, Privileges, and Access Controls

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.