CVE-2026-0892 | Memory safety bugs fixed in Firefox 147 and Thunderbird 147

Memory safety bugs present in Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 147 and Thunderbird 147.

Published: 2026-01-13 Last update: 2026-04-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-0892 is rated Moderate Risk (41.1/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-0892

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-18 0.05% 0.02% -0.03%
2 2026-01-19 0.04% 0.05% +0.01%
3 2026-01-14 0.04%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-0892

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-0892

OS Trackers for CVE-2026-0892

vendor priority summary link
alpine CVE-2026-0892: 2 source package rows (firefox, thunderbird); 180 state rows across 2 repos (3.23-community, edge-community); fixed 0, open 180. https://security.alpinelinux.org/vuln/CVE-2026-0892
debian not yet assigned CVE-2026-0892 not yet assigned priority: Debian including 1 source packages (firefox), 1 status rows across 1 suites (sid): resolved 1. https://security-tracker.debian.org/tracker/CVE-2026-0892
redhat medium https://access.redhat.com/security/cve/CVE-2026-0892
suse high https://www.suse.com/security/cve/CVE-2026-0892/
ubuntu medium CVE-2026-0892 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 58 status rows across 8 suites (bionic, focal, jammy, noble, plucky, questing, resolute, upstream): DNE 29, needs-triage 10, not-affected 10, ignored 9. https://ubuntu.com/security/CVE-2026-0892

Affected software / configurations for CVE-2026-0892

Vendor Product Version Raw CPE
mozilla firefox < 147.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
mozilla thunderbird < 147.0 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*

References for CVE-2026-0892

cvelogic Threat Intelligence