CVE-2020-26978
Using techniques that built on the slipstream research, a malicious webpage could have exposed both an internal network's hosts as well as services running on the user's local machine.
Does this matter?
Lower severity and a low EPSS score (1.33%). Track it; it rarely justifies an emergency change on its own.
Description
Using techniques that built on the slipstream research, a malicious webpage could have exposed both an internal network's hosts as well as services running on the user's local machine. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 1.33% probability · 71th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 1.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1677047Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2020-54/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-55/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-56/Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1677047Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2020-54/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-55/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-56/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.