CVE-2025-2857
The original vulnerability was being exploited in the wild. *This only affects Firefox on Windows.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.90%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Following the recent Chrome sandbox escape (CVE-2025-2783), various Firefox developers identified a similar pattern in our IPC code. A compromised child process could cause the parent process to return an unintentionally powerful handle, leading to a sandbox escape. The original vulnerability was being exploited in the wild. *This only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability was fixed in Firefox 136.0.4, Firefox ESR 128.8.1, and Firefox ESR 115.21.1.
- CVSS 3.1
- 10.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 1.90% probability · 79th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-668
- Affected
- mozilla/firefox
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1956398Permissions Required
- https://issues.chromium.org/issues/405143032Permissions Required
- https://www.cve.org/CVERecord?id=CVE-2025-2783Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-19/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.