CVE-2026-4727 — Uncontrolled Resource Consumption in Mozilla Firefox

CWE-400 — Uncontrolled Resource ConsumptionCWE-770 — Allocation of Resources Without Limits or Throttling9 documents8 sources
Severity
7.5HIGHNVD
EPSS
0.0%
top 96.03%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Mozilla FirefoxMozilla Thunderbird
Timeline
PublishedMar 24

Description

Denial-of-service in the Libraries component in NSS. This vulnerability was fixed in Firefox 149 and Thunderbird 149.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages2 packages

▶NVDmozilla/firefox< 149.0
▶NVDmozilla/thunderbird< 149.0

🔴Vulnerability Details

3
OSV
CVE-2026-4727: Denial-of-service in the Libraries component in NSS↗2026-03-24
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GHSA
GHSA-f58q-fr7j-32m6: Denial-of-service in the Libraries component in NSS↗2026-03-24
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CVEList
Denial-of-service in the Libraries component in NSS↗2026-03-24
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📋Vendor Advisories

4
Red Hat
firefox: Denial-of-service in the Libraries component in NSS↗2026-03-24
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Debian
CVE-2026-4727: firefox - Denial-of-service in the Libraries component in NSS. This vulnerability affects ...↗2026
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Mozilla
Mozilla Foundation Security Advisory 2026-23: CVE-2026-4727↗
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Mozilla
Mozilla Foundation Security Advisory 2026-20: CVE-2026-4727↗
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🕵️Threat Intelligence

1
Wiz
CVE-2026-4727 Impact, Exploitability, and Mitigation Steps | Wiz↗
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CVE-2026-4727 — Uncontrolled Resource Consumption | cvebase