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Vulnerability details: VCID-wpy7-gpn8-euhx
Vulnerability ID VCID-wpy7-gpn8-euhx
Aliases CVE-2021-23979
Summary Mozilla developers Tyson Smith, Lars T Hansen, Valentin Gosu, and Sebastian Hengst reported memory safety bugs present in Firefox 85. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.
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 0.00323 https://api.first.org/data/v1/epss?cve=CVE-2021-23979
cvssv3.1 8.1 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
archlinux High https://security.archlinux.org/AVG-1599
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-2021-23979
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
AVG-1599 https://security.archlinux.org/AVG-1599
mfsa2021-07 https://www.mozilla.org/en-US/security/advisories/mfsa2021-07
USN-4756-1 https://usn.ubuntu.com/4756-1/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H 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 0.55605
EPSS Score 0.00323
Published At May 29, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-05-29T08:26:32.984556+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2021/mfsa2021-07.yml 38.6.0