Secuno
ENNL
Book demo

CVE-2025-2857

Mozilla Firefox vulnerability

10.0 CRITICALEPSS 1.94%
  1. Published27 Mar 2025

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 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

Mozilla Firefox< 136.0.4 · ≥ 128.1.0 < 128.8.1 · < 115.21.1

Remediation

Fixed in
Mozilla Firefox≥ 136.0.4

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-1021258.8
The sandbox that isolates document conversion on a Kiteworks appliance did not fully…
CVE-2026-545048.8
MCP Documentation Server is a local-first document management and semantic search…
CVE-2026-9294010.0
vm2 versions 3.11.3 through 3.11.6 expose the host process's real https.globalAgent to…
CVE-2026-850538.8
Improper resource exposure in CacheStorage in Google Chrome prior to 152.0.7977.82…
CVE-2026-738439.6
OpenChoreo is a complete, open-source developer platform for Kubernetes. Prior to 1.0.2…
CVE-2026-727648.8
n8n's JavaScript task runner shared a single module cache across all users' Code-node…

Frequently asked

Is CVE-2025-2857 being actively exploited?

CVE-2025-2857 is not in the CISA KEV catalog. Its EPSS exploit probability is 1.94%.

How severe is CVE-2025-2857?

CVE-2025-2857 has a CVSS 3.1 base score of 10.0, rated critical. EPSS estimates a 1.94% probability of exploitation.

Which products are affected by CVE-2025-2857?

Affected products include Mozilla Firefox.

How do I fix CVE-2025-2857?

Upgrade affected software to a fixed version, for example Mozilla Firefox 136.0.4 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-2857 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.