CVE-2023-23601Public exploitNetwork attack vector

Website spoofing via cross-origin same-tab URL dragging

Published Jun 2, 2023 · Updated Dec 18, 2025

Origin validation error in Firefox, Firefox ESR, and Thunderbird allows remote attackers to spoof websites through cross-origin URL dragging. The same-tab drop handler allowed a URL from a cross-origin iframe to navigate the enclosing tab because it did not compare the source and target WindowContext. Firefox before 109 and Firefox ESR and Thunderbird before 102.7 are affected; exploitation requires a user to drag iframe content into the surrounding page.

CVSS severity6.5
Medium
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Origin validation error in Firefox, Firefox ESR, and Thunderbird allows remote attackers to spoof websites through cross-origin URL dragging. The same-tab drop handler allowed a URL from a cross-origin iframe to navigate the enclosing tab because it did not compare the source and target WindowContext. Firefox before 109 and Firefox ESR and Thunderbird before 102.7 are affected; exploitation requires a user to drag iframe content into the surrounding page.

The record

CVE
CVE-2023-23601
Published
Jun 2, 2023
Updated
Dec 18, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-346, T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <109

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <109
Mozilla · Thunderbirdversion=unspecified <102.7
Mozilla · Firefox ESRversion=unspecified <102.7

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-346Origin Validation Error
T1036Masquerading

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo