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VulnerabilityPublished Updated

CVE-2025-3028: Mozilla Firefox · Use After Free

Affects Mozilla FirefoxSource CVE Database V5

0

Not known to be exploited · CVSS 6.5 Medium : upgrade to 137 when convenient.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score
6.5Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.8% chance of exploitation in 30 days – higher than 58% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 137
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 1 Apr 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: 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 26 Oct 2026.

What to do

Upgrade Mozilla Firefox to 137.

Affected software

ProductAffectedFixed in
Mozilla FirefoxAffected
  • <137
Fixed in
  • 137

AI-suggested

Mozilla has released official fixes for this vulnerability in Firefox 137, Firefox ESR 115.22, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9. Users and administrators should update to these versions or later to remediate the vulnerability. Since this is not a cloud service, patching the client software is required. There are no vendor advisories indicating that no action is required or that the issue is already mitigated without patching. Patch status is confirmed as fixed in the specified versions.

Description

JavaScript code running while transforming a document with the XSLTProcessor could lead to a use-after-free. This vulnerability was fixed in Firefox 137, Firefox ESR 115.22, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9.

References

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