Cross-origin cookie disclosure and modification
Published Jun 16, 2026 · Updated Jun 16, 2026
Same-origin policy bypass in Mozilla Firefox and Thunderbird before 152 allows remote attackers to read or alter cross-origin cookie data. Mozilla has not published the flawed cookie-processing operation or the attacker-controlled input that triggers the origin validation failure. No authentication or user interaction is required; affected ESR releases are before 140.12, while Thunderbird limits exposure by disabling scripting when reading email.
Summary
What happened
Same-origin policy bypass in Mozilla Firefox and Thunderbird before 152 allows remote attackers to read or alter cross-origin cookie data. Mozilla has not published the flawed cookie-processing operation or the attacker-controlled input that triggers the origin validation failure. No authentication or user interaction is required; affected ESR releases are before 140.12, while Thunderbird limits exposure by disabling scripting when reading email.
The record
- CVE
- CVE-2026-12304
- Published
- Jun 16, 2026
- Updated
- Jun 16, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-346
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 16, 2026CVE publishedPublication date reported by the CVE source.
- Jun 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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