CVE-2020-15669

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-10-01 · updated 2026-06-17
Weakness: CWE-416

Description

When aborting an operation, such as a fetch, an abort signal may be deleted while alerting the objects to be notified. This results in a use-after-free and we presume that with enough effort it could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 68.12 and Thunderbird < 68.12.

Affected products

Mozilla Firefox ESR: before 68.12 — fixed in 68.12
Mozilla Thunderbird: before 68.12 — fixed in 68.12

How to fix

Upgrade to a fixed version: Mozilla Firefox ESR 68.12; Mozilla Thunderbird 68.12. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1656957
https://www.mozilla.org/security/advisories/mfsa2020-37/
https://www.mozilla.org/security/advisories/mfsa2020-40/
https://bugzilla.mozilla.org/show_bug.cgi?id=1656957
https://www.mozilla.org/security/advisories/mfsa2020-37/
https://www.mozilla.org/security/advisories/mfsa2020-40/

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