CVE-2025-10529

MEDIUM 6.5CVE-2025-10529 · Published 16/09/2025 · updated 23/10/2026

In short

CVE-2025-10529 is a MEDIUM (CVSS 6.5) vulnerability affecting firefox (mozilla), thunderbird (mozilla).
Chance of exploitation in the next 30 days (EPSS): 0.32%, higher than 24.7% of all vulnerabilities.
Fix: update to 140.3.0, 143.0 or later.

Package	Affected versions	Patched versions
firefox mozilla	`< 140.3.0< 143.0`	`140.3.0143.0`
thunderbird mozilla	`< 143.0`	`143.0`

Description

Same-origin policy bypass in the Layout component. This vulnerability was fixed in Firefox 143, Firefox ESR 140.3, Thunderbird 143, and Thunderbird 140.3.

References

bugzilla.mozilla.org/show_bug.cgi · Permissions Required
mozilla.org/security/advisories/mfsa2025-73 · Vendor Advisory
mozilla.org/security/advisories/mfsa2025-75 · Vendor Advisory
mozilla.org/security/advisories/mfsa2025-77 · Vendor Advisory
mozilla.org/security/advisories/mfsa2025-78 · Vendor Advisory
lists.debian.org/debian-lts-announce/2025/09/msg00020.html
lists.debian.org/debian-lts-announce/2025/09/msg00026.html

More vulnerabilities in firefox

See all →

Running one of these products? Scan your site to see whether it exposes a vulnerable version.

Scan my site free

Package

Affected versions

Patched versions

firefox

mozilla

< 140.3.0< 143.0

140.3.0143.0

thunderbird

mozilla

< 143.0

143.0

More vulnerabilities in firefox

See all →