CVE-2025-2857

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

10.0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

2.0% chance of exploitation in the next 30 days; higher than 80% of CVEs (scores of 2026-10-25)

CWE

CWE-668

Published

2025-03-27

Modified

2026-10-05

Record from

the NVD, synced 2026-10-19

Affected

• mozilla:firefox

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1956398
• https://issues.chromium.org/issues/405143032
• https://www.cve.org/CVERecord?id=CVE-2025-2783
• https://www.mozilla.org/security/advisories/mfsa2025-19/

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