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Vulnerability details: VCID-vque-dfjx-ryad
Vulnerability ID VCID-vque-dfjx-ryad
Aliases CVE-2021-23976
Summary When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites.*Note: This issue is a different issue from CVE-2020-26954 and only affected Firefox for Android. Other operating systems are unaffected.*
Status Published
Exploitability None
Weighted Severity None
Risk None
Affected and Fixed Packages Package Details
Weaknesses (0)
There are no known CWE.
System Score Found at
epss 0.00268 https://api.first.org/data/v1/epss?cve=CVE-2021-23976
cvssv3.1 6.3 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
archlinux Medium https://security.archlinux.org/AVG-1600
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2021-07
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-23976
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
AVG-1600 https://security.archlinux.org/AVG-1600
GLSA-202104-10 https://security.gentoo.org/glsa/202104-10
mfsa2021-07 https://www.mozilla.org/en-US/security/advisories/mfsa2021-07
No exploits are available.
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:N Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.50461
EPSS Score 0.00268
Published At May 29, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-05-29T08:26:32.876419+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2021/mfsa2021-07.yml 38.6.0