CVE-2026-3847 | Memory safety bugs fixed in Firefox 148.0.2

Memory safety bugs present in Firefox 148.0.2. 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 148.0.2.

Published: 2026-03-10 Last update: 2026-04-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-3847 is rated Moderate Risk (43.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.31%). 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-2026-3847

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 2026-06-15 0.06% 0.31% +0.25%
2 2026-05-17 0.04% 0.06% +0.02%
3 2026-03-11 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-3847

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
 2.8 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-3847

OS Trackers for CVE-2026-3847

vendor priority summary link
alpine — CVE-2026-3847: 1 source package rows (firefox); 128 state rows across 2 repos (3.23-community, edge-community); fixed 0, open 128. https://security.alpinelinux.org/vuln/CVE-2026-3847
debian not yet assigned CVE-2026-3847 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-2026-3847
suse high CVE-2026-3847 severity important: SUSE including 14 source package names (MozillaFirefox, MozillaFirefox-148.0.2-1.1, …), 88 product×package rows across 24 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, … (24 product lines)): Known Not Affected 83, Fixed 5. https://www.suse.com/security/cve/CVE-2026-3847/
ubuntu medium CVE-2026-3847 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 40 status rows across 6 suites (bionic, focal, jammy, noble, questing, upstream): DNE 16, needs-triage 10, ignored 8, not-affected 5, needed 1. https://ubuntu.com/security/CVE-2026-3847

Affected software / configurations for CVE-2026-3847

Vendor Product Version Raw CPE
mozilla firefox < 148.0.2 cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*

References for CVE-2026-3847

cvelogic Threat Intelligence