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VulnerabilityPublished Updated

CVE-2026-4726: Mozilla Firefox · Uncontrolled Resource Consumption

Affects Mozilla FirefoxSource CVE Database V5

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Not known to be exploited · CVSS 7.5 High · patch available : patch Mozilla Firefox soon.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 24 Mar 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Mozilla FirefoxAffected
  • <149
Fixed in
  • 149

AI-suggested

Mozilla has released an official fix for this vulnerability in Firefox 149. Users and administrators should update to Firefox 149 or later to remediate this issue. No additional mitigation steps are required once the update is applied.

Description

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

References

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