CVE-2025-2857

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 affects Firefox < 136.0.4, Firefox ESR < 128.8.1, and Firefox ESR < 115.21.1.

10.0

CVSS

Severity: Critical

CVSS 3.1 •

EPSS 0.09%

Vendor Advisory mozilla.org

Affected: Mozilla Firefox

Affected: Mozilla Firefox ESR

References

Link	Tags
https://bugzilla.mozilla.org/show_bug.cgi?id=1956398	permissions required
https://issues.chromium.org/issues/405143032	permissions required
https://www.cve.org/CVERecord?id=CVE-2025-2783	third party advisory
https://www.mozilla.org/security/advisories/mfsa2025-19/	vendor advisory

Frequently Asked Questions

What is the severity of CVE-2025-2857?: CVE-2025-2857 has been scored as a critical severity vulnerability.
How to fix CVE-2025-2857?: To fix CVE-2025-2857, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-2857 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2025-2857 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-2857?: CVE-2025-2857 affects Mozilla Firefox, Mozilla Firefox ESR, Mozilla Firefox ESR.

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