CVE-2025-3859

Firefox Focus elide URL allows address bar spoofing

MEDIUM
6.1
CVSS Score
Published: April 30, 2025 at 04:30 PM UTC
Updated: June 17, 2026 at 09:20 AM UTC
1 product affected across 1 vendorFirefox Focus

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage This vulnerability affects Focus < 138.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 138.0
Vendor states this is fixed in 138 (unaffected)
Affected range stops below 138.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-601CWE-451

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