Information Disclosure in Firefox and Firefox ESR Products by Mozilla
CVE-2026-6765

5.3MEDIUM

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
21 April 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-6765?

This vulnerability involves an information disclosure flaw in the Form Autofill component of Firefox and Firefox ESR. When exploited, it can reveal sensitive user data. Mozilla has addressed this issue in versions 150 of Firefox and 140.10 of Firefox ESR, emphasizing the importance of updating to the latest versions to ensure user security.

Affected Version(s)

Firefox 140.10

Firefox 150

Thunderbird 140.10

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

SkeletonKey
Created by defineid

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2022419
https://www.mozilla.org/security/advisories/mfsa2026-30/
https://www.mozilla.org/security/advisories/mfsa2026-32/

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

ABDULAZIZ ALASAIQAH
.