What’s Vulnerable › Vulnerabilities

CVE-2020-15653

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-08-10 · updated 2026-06-17

Description

An iframe sandbox element with the allow-popups flag could be bypassed when using noopener links. This could have led to security issues for websites relying on sandbox configurations that allowed popups and hosted arbitrary content. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Affected products

• Canonical Ubuntu Linux: 16.04, 18.04, 20.04
• Mozilla Firefox: before 79.0 — fixed in 79.0
• Mozilla Firefox ESR: before 78.1 — fixed in 78.1
• Mozilla Thunderbird: before 78.1 — fixed in 78.1

How to fix

Upgrade to a fixed version: Mozilla Firefox 79.0; Mozilla Firefox ESR 78.1; Mozilla Thunderbird 78.1. Check the vendor advisory for mitigations.

References

• http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00025.html
• https://bugzilla.mozilla.org/show_bug.cgi?id=1521542
• https://usn.ubuntu.com/4443-1/
• https://www.mozilla.org/security/advisories/mfsa2020-30/
• https://www.mozilla.org/security/advisories/mfsa2020-32/
• https://www.mozilla.org/security/advisories/mfsa2020-33/
• http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00025.html
• https://bugzilla.mozilla.org/show_bug.cgi?id=1521542
• https://usn.ubuntu.com/4443-1/
• https://www.mozilla.org/security/advisories/mfsa2020-30/
• https://www.mozilla.org/security/advisories/mfsa2020-32/
• https://www.mozilla.org/security/advisories/mfsa2020-33/

Get alerted when CVE-2020-15653 or the next vulnerability affects your stack