CVE-2026-84127

Information disclosure in the WebExtensions component in Firefox for Android

4.3 Medium

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required

What an attacker can affect

Confidentiality: Low
Integrity: None
Availability: None

Exploit likelihood

0.26%Up 0.1 points since Sep 2, 2026

What each source reports

CVE List Score used 4.3

Information disclosure in the WebExtensions component in Firefox for Android

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.

Record: CVE-2026-84127
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Weakness: CWE-200
Updated: 2026-11-02

EUVDEUVD-2026-69076 4.3

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.

Record: EUVD-2026-69076
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-jvhv-r392-774p 4.3

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability...

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.

Record: GHSA-jvhv-r392-774p
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Weakness: CWE-200
Updated: 2026-11-02

NVD 4.3

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.

Record: CVE-2026-84127
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Weakness: CWE-200
Updated: 2026-11-02

OSV 4.3

Information disclosure in the WebExtensions component in Firefox for Android

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.

Record: CVE-2026-84127
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-84127 4.3

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.

Record: UBUNTU-CVE-2026-84127
CVSS 3.1: 4.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Updated: 2026-11-02

OSVopenSUSE-SU-2026:11677-1 No score

MozillaFirefox-155.0-1.1 on GA media

These are all security issues fixed in the MozillaFirefox-155.0-1.1 package on the GA media of openSUSE Tumbleweed.

Record: openSUSE-SU-2026:11677-1
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`mozjs52` Ubuntu:18.04:LTS	All versions, plus listed versions 52.3.1-0ubuntu352.3.1-7fakesync152.8.1-0ubuntu0.18.04.152.9.1-0ubuntu0.18.04.1	None known
`mozjs38` Ubuntu:18.04:LTS	All versions, plus listed versions 38.8.0~repack1-0ubuntu138.8.0~repack1-0ubuntu338.8.0~repack1-0ubuntu4	None known
`mozjs68` Ubuntu:20.04:LTS	All versions, plus listed versions 68.5.0-1~fakesync68.5.0-2~fakesync68.6.0-168.6.0-1ubuntu1	None known
`mozjs52` Ubuntu:20.04:LTS	All versions, plus listed versions 52.9.1-1build152.9.1-1ubuntu3	None known
`mozjs102` Ubuntu:22.04:LTS	All versions, plus listed versions 102.11.0-0ubuntu0.22.04.1102.12.0-0ubuntu0.22.04.1102.13.0-0ubuntu0.22.04.1102.15.1-0ubuntu0.22.04.1	None known
`mozjs78` Ubuntu:22.04:LTS	All versions, plus listed versions 78.13.0-178.15.0-278.15.0-4ubuntu1	None known
`mozjs91` Ubuntu:22.04:LTS	All versions, plus listed versions 91.5.1-0ubuntu191.6.0-191.6.0-291.7.0-291.10.0-0ubuntu1	None known
`thunderbird` Ubuntu:22.04:LTS	All versions, plus listed versions 1:91.1.2+build1-0ubuntu11:91.3.0+build2-0ubuntu11:91.3.1+build1-0ubuntu11:91.3.2+build1-0ubuntu11:91.4.0+build1.1-0ubuntu1 Show 34 moreShow less 1:91.4.0+build2-0ubuntu11:91.5.0+build1-0ubuntu11:91.5.1+build1-0ubuntu11:91.6.1+build1-0ubuntu11:91.7.0+build1-0ubuntu11:91.7.0+build2-0ubuntu11:91.8.0+build2-0ubuntu11:91.9.1+build1-0ubuntu0.22.04.11:91.11.0+build2-0ubuntu0.22.04.11:102.2.2+build1-0ubuntu0.22.04.11:102.4.2+build2-0ubuntu0.22.04.11:102.7.1+build2-0ubuntu0.22.04.11:102.8.0+build2-0ubuntu0.22.04.11:102.9.0+build1-0ubuntu0.22.04.11:102.10.0+build2-0ubuntu0.22.04.11:102.11.0+build1-0ubuntu0.22.04.11:102.13.0+build1-0ubuntu0.22.04.11:102.15.0+build1-0ubuntu0.22.04.11:102.15.1+build1-0ubuntu0.22.04.11:115.3.1+build1-0ubuntu0.22.04.21:115.4.1+build1-0ubuntu0.22.04.11:115.5.0+build1-0ubuntu0.22.04.11:115.6.0+build2-0ubuntu0.22.04.11:115.8.1+build1-0ubuntu0.22.04.11:115.9.0+build1-0ubuntu0.22.04.11:115.10.1+build1-0ubuntu0.22.04.11:115.11.0+build2-0ubuntu0.22.04.11:115.12.0+build3-0ubuntu0.22.04.11:115.13.0+build5-0ubuntu0.22.04.11:115.15.0+build1-0ubuntu0.22.04.11:115.16.0+build2-0ubuntu0.22.04.11:115.18.0+build1-0ubuntu0.22.04.11:128.12.0+build1-0ubuntu0.22.04.11:140.7.1+build1-0ubuntu0.22.04.1	None known
`mozjs102` Ubuntu:24.04:LTS	All versions, plus listed versions 102.15.1-1102.15.1-3ubuntu2	None known
`mozjs115` Ubuntu:24.04:LTS	All versions, plus listed versions 115.3.0-0ubuntu1115.4.0-2115.5.0-1115.6.0-1115.7.0-4 Show 4 moreShow less 115.8.0-1115.9.0-1115.9.0-1build1115.10.0-1	None known
`MozillaFirefox` openSUSE:Tumbleweed From an advisory covering 29 CVEs	before 155.0-1.1	155.0-1.1

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-84127 is a medium vulnerability (CVSS 4.3) in Mozilla Firefox, published September 1, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 17th percentile. No source names a fixed version.

References

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