CVE-2023-23606: Mozilla Firefox · Out-of-bounds Write
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 8.8 High : upgrade to 109 soon.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 109
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 2 Jun 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 109.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in
|
AI-suggested
- Immediate upgrade to Mozilla Firefox version 109 or later, as this version addresses the vulnerability.
- Implement application whitelisting and endpoint protection solutions that can detect and block exploitation attempts targeting memory corruption.
- Employ browser security features such as sandboxing, strict content security policies (CSP), and disabling unnecessary plugins or extensions that could increase attack surface.
- Conduct user awareness training to recognize phishing and suspicious links, minimizing risky user interactions that could trigger exploitation.
- Monitor network traffic and endpoint logs for unusual behavior indicative of exploitation attempts, such as unexpected process launches or memory anomalies.
- Use network-level protections like web filtering and intrusion detection systems to block access to known malicious sites.
- Maintain an up-to-date inventory of browser versions in use across the organization to ensure compliance with security patches.
- Consider deploying browser isolation technologies for high-risk users or sensitive environments to contain potential exploits.
Description
Mozilla developers and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 108. 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 < 109.