What’s Vulnerable › Vulnerabilities

CVE-2020-6798

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-03-02 · updated 2026-06-17
• Weakness: CWE-79

Description

If a template tag was used in a select tag, the parser could be confused and allow JavaScript parsing and execution when it should not be allowed. A site that relied on the browser behaving correctly could suffer a cross-site scripting vulnerability as a result. In general, this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled when reading mail, but is potentially a risk in browser or browser-like contexts. This vulnerability affects Thunderbird < 68.5, Firefox < 73, and Firefox < ESR68.5.

Affected products

• Mozilla Firefox: before 73.0 — fixed in 73.0
• Mozilla Firefox ESR: before 68.5.0 — fixed in 68.5.0
• Mozilla Thunderbird: before 68.5.0 — fixed in 68.5.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 73.0; Mozilla Firefox ESR 68.5.0; Mozilla Thunderbird 68.5.0. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1602944
• https://security.gentoo.org/glsa/202003-02
• https://security.gentoo.org/glsa/202003-10
• https://usn.ubuntu.com/4278-2/
• https://usn.ubuntu.com/4328-1/
• https://usn.ubuntu.com/4335-1/
• https://www.mozilla.org/security/advisories/mfsa2020-05/
• https://www.mozilla.org/security/advisories/mfsa2020-06/
• https://www.mozilla.org/security/advisories/mfsa2020-07/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1602944
• https://security.gentoo.org/glsa/202003-02
• https://security.gentoo.org/glsa/202003-10

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