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VulnerabilityPublished Updated

CVE-2024-6615: Mozilla Firefox · Out-of-bounds Write

Affects Mozilla FirefoxSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High : upgrade to 128 soon.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 128
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 9 Jul 2024

  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 128.

Affected software

ProductAffectedFixed in
Mozilla FirefoxAffected
  • <128
Fixed in
  • 128

AI-suggested

1. Immediately plan and deploy updates to Firefox 128 and Thunderbird 128 or later once patches are officially released by Mozilla. 2. If you cannot patch yet, consider implementing network-level protections such as blocking access to known malicious domains and employing web filtering to reduce exposure to malicious websites. 3. Enhance email security by deploying advanced phishing detection and sandboxing solutions to prevent delivery of crafted emails that could trigger the vulnerability. 4. Conduct targeted user awareness training focusing on the risks of clicking unknown links or opening suspicious attachments. 5. Monitor endpoint and network logs for unusual behavior indicative of exploitation attempts, such as unexpected process launches or network connections. 6. Employ application whitelisting and endpoint detection and response (EDR) tools to detect and block exploitation attempts. 7. Coordinate with IT and security teams to ensure rapid incident response capability in case of exploitation. 8. Review and tighten browser security settings, including disabling unnecessary plugins and enabling content security policies where feasible.

Description

Memory safety bugs present in Firefox 127 and Thunderbird 127. 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 affects Firefox < 128 and Thunderbird < 128.

References

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