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Full vulnerability report · 2025
CVE-2025-2857High confidence

Incorrect handle could lead to sandbox escapes

Mozilla · Firefox

10.0CriticalCVSS 3.1
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2025-8495

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
01

What, why and how

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.

What

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.

Why

The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Exposure of Resource to Wrong Sphere → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-668 ↗

CWE-668: Exposure of Resource to Wrong Sphere. The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-668
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2025-0651Mozilla Firefox und Firefox ESR: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Mozilla Firefox und Mozilla Firefox ESR ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0756Multiples vulnérabilités dans les produits VMware

ecord?id=CVE-2025-27113 Référence CVE CVE-2025-27144 https://www.cve.org/CVERecord?id=CVE-2025-27144 Référence CVE CVE-2025-27210 https://www.cve.org/CVERecord?id=CVE-2025-27210 Référence CVE CVE-2025-27516 https://www.cve.org/CVERecord?id=CVE-2025-27516 Référence CVE CVE-2025-27587 https://www.cve.org/CVERecord?id=CVE-2025-27587 Référence CVE CVE-2025-27817 https://www.cve.org/CVERecord?id=CVE-2025-27817 Référence CVE CVE-2025-27818 https://www.cve.org/CVERecord?id=CVE-2025-27818 Référence CVE CVE-2025-2783 https://www.cve.org/CVERecord?id=CVE-2025-2783 Référence CVE CVE-2025-2817 https://www.cve.org/CVERecord?id=CVE-2025-2817 Référence CVE CVE-2025-2857 https://www.cve.org/CVERecord?id=CVE-2025-2857 Référence CVE CVE-2025-29087 https://www.cve.org/CVERecord?id=CVE-2025-29087 Référence CVE CVE-2025-29088 https://www.cve.org/CVERecord?id=CVE-2025-29088 Référence CVE CVE-2025-30204 https://www.cve.org/CVERecord?id=CVE-2025-30204 Référence CVE CVE-2025-30258 https://www.cve.org/CVERecord?id=CVE-2025-30258 Référence CVE CVE-2025-3028 https://www.cve.org/CVERecord?id=CVE-2025-3028 Référence CVE CVE-2025-3029 https://www.cve.org/CVERecord?id=CVE-2025-3029 Référence CVE CVE-2025-3030 https://www.cve.org/CVERecord?id=CVE-2025-3030 Référence CVE CVE-2025-3031 https://www.cve.org/CVERecord?id=CVE-2025

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0251Vulnérabilité dans Mozilla Firefox

Une vulnérabilité a été découverte dans Mozilla Firefox. Elle permet à un attaquant de provoquer un contournement de la politique de sécurité.

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
See the vendor and CVE records for the affected range.
Fixed
115.21.1 ≤ 115.*; 128.8.1 ≤ 128.*; 136.0.4 ≤ *
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 27 Mar 2025 · Last source change 9 Jun 2026, 16:23 UTC · CWE-668 · Exposure of Resource to Wrong Sphere

CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-8495
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD modified after enrichment

Missing structured fields: affected versions. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2025-8495↗Vendor advisory↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2025-2857 · cve.blacktree.nl