CVE-2020-26972
The lifecycle of IPC Actors allows managed actors to outlive their manager actors; and the former must ensure that they are not attempting to use a dead actor they have a reference to.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
The lifecycle of IPC Actors allows managed actors to outlive their manager actors; and the former must ensure that they are not attempting to use a dead actor they have a reference to. Such a check was omitted in WebGL, resulting in a use-after-free and a potentially exploitable crash. This vulnerability affects Firefox < 84.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.31% probability · 70th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- mozilla/firefox
- 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=1671382Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2020-54/Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1671382Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2020-54/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.