What’s Vulnerable › Vulnerabilities

CVE-2025-1013: Potential opening of private browsing tabs in normal browsing windows

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-02-04 · updated 2026-10-05
• Weakness: CWE-362

Description

A race condition could have led to private browsing tabs being opened in normal browsing windows. This could have resulted in a potential privacy leak. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

Affected products

• Mozilla Firefox: before 128.7.0; before 135.0 — fixed in 128.7.0, 135.0
• Mozilla Thunderbird: before 128.7.0; from 129.0 before 135.0 — fixed in 128.7.0, 135.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 128.7.0, 135.0; Mozilla Thunderbird 128.7.0, 135.0. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1932555
• https://www.mozilla.org/security/advisories/mfsa2025-07/
• https://www.mozilla.org/security/advisories/mfsa2025-09/
• https://www.mozilla.org/security/advisories/mfsa2025-10/
• https://www.mozilla.org/security/advisories/mfsa2025-11/
• https://lists.debian.org/debian-lts-announce/2025/02/msg00006.html

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