In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition. This vulnerability affects Firefox < 82.0.3, Firefox ESR < 78.4.1, and Thunderbird < 78.4.2.
Loading...
Loading...
Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 8.8; sources differ by 0.0.
In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition. This vulnerability affects Firefox < 82.0.3, Firefox ESR < 78.4.1, and Thunderbird < 78.4.2.
December 9, 2020
November 21, 2024
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | xul-ext-lightning (1:78.5.0+build3-0ubuntu0.20.10.1) @ groovy | 2026-05-23 | ubuntu |
| ubuntu | firefox-mozsymbols (82.0.3+build1-0ubuntu0.16.04.1) @ xenial | 2026-05-23 | ubuntu |
| redhat | thunderbird-0:78.4.3-1.el6_10 | 2020-11-23 | redhat |
| redhat | thunderbird-0:78.4.3-1.el8_2 | 2020-11-23 | redhat |
| redhat | thunderbird-0:78.4.3-1.el8_0 | 2020-11-23 | redhat |
| redhat | thunderbird-0:78.4.3-1.el8_1 | 2020-11-23 | redhat |
| redhat | thunderbird-0:78.4.3-1.el7_9 | 2020-11-23 | redhat |
| redhat | thunderbird-0:78.4.3-1.el8_3 | 2020-11-18 | redhat |
| redhat | firefox-0:78.4.1-1.el8_1 | 2020-11-17 | redhat |
| redhat | firefox-0:78.4.1-1.el8_0 | 2020-11-17 | redhat |
| redhat | firefox-0:78.4.1-1.el8_2 | 2020-11-17 | redhat |
| redhat | firefox-0:78.4.1-1.el6_10 | 2020-11-12 | redhat |
| redhat | firefox-0:78.4.1-1.el8_3 | 2020-11-12 | redhat |
| redhat | firefox-0:78.4.1-1.el7_9 | 2020-11-12 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
RHSA-2020:5099 — Critical
RHSA-2020:5100 — Critical
RHSA-2020:5104 — Critical
RHSA-2020:5135 — Critical
RHSA-2020:5138 — Critical
RHSA-2020:5139 — Critical
RHSA-2020:5146 — Critical
RHSA-2020:5162 — Critical
RHSA-2020:5163 — Critical
RHSA-2020:5164 — Critical
RHSA-2020:5166 — Critical
RHSA-2020:5167 — Critical
Firefox vulnerability
Thunderbird vulnerabilities
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Working exploit code is in the public domain (1 Metasploit module). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
Firefox MCallGetProperty Write Side Effects Use After Free Exploit
Open source ↗See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-26950
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.
redhat
CWE-416