CVE-2025-2857 | Incorrect handle could lead to sandbox escapes

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.

Published: 2025-03-27 Last update: 2026-04-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-2857 is rated Moderate Risk (54.8/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.20%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-2857

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-05 0.06% 0.20% +0.14%
2 2026-05-03 0.15% 0.06% -0.09%
3 2026-04-22 — 0.15% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-2857

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
10.0 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 6.0 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-2857

OS Trackers for CVE-2025-2857

vendor priority summary link
alpine — CVE-2025-2857: 2 source package rows (firefox, firefox-esr); 280 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 280. https://security.alpinelinux.org/vuln/CVE-2025-2857
debian unimportant CVE-2025-2857 unimportant priority: Debian including 2 source packages (firefox, firefox-esr), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-2857
redhat — — https://access.redhat.com/security/cve/CVE-2025-2857

Affected software / configurations for CVE-2025-2857

Vendor Product Version Raw CPE
mozilla firefox < 136.0.4 cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
mozilla firefox < 115.21.1 cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
mozilla firefox >= 128.1.0, < 128.8.1 cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*

References for CVE-2025-2857

cvelogic Threat Intelligence