Mozilla Foundation Security Advisory 2025-52

Security Vulnerabilities fixed in Firefox ESR 115.25

Announced
June 24, 2025
Impact
high
Products
Firefox ESR
Fixed in
  • Firefox ESR 115.25

#CVE-2025-6424: Use-after-free in FontFaceSet

Reporter
LJP and HexRabbit (DEVCORE Research Team)
Impact
high
Description

A use-after-free in FontFaceSet resulted in a potentially exploitable crash.

References

#CVE-2025-6425: The WebCompat WebExtension shipped with Firefox exposed a persistent UUID

Reporter
Rob Wu
Impact
moderate
Description

An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles.

References