CVE-2021-23983

high

Published — · Modified —

CVSS v3

—

CVSS v2

—

VIR risk

8.0

Description

By causing a transition on a parent node by removing a CSS rule, an invalid property for a marker could have been applied, resulting in memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 87.

Predictions

Exploit likelihood

20%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-23983

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-23983.html

OS impact

OS	Version	Status	Fixed in
arch		fixed	`87.0-1`
sles		affected
debian	sid	fixed	`87.0-1`

References

https://www.suse.com/security/cve/CVE-2021-23983.html
https://security-tracker.debian.org/tracker/CVE-2021-23983

Verify integrity in audit chain (admin only). AS-IS.