What’s Vulnerable › Vulnerabilities

CVE-2023-5174

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-09-27 · updated 2026-06-17
• Weakness: CWE-416

Description

If Windows failed to duplicate a handle during process creation, the sandbox code may have inadvertently freed a pointer twice, resulting in a use-after-free and a potentially exploitable crash. *This bug only affects Firefox on Windows when run in non-standard configurations (such as using `runas`). Other operating systems are unaffected.* This vulnerability affects Firefox < 118, Firefox ESR < 115.3, and Thunderbird < 115.3.

Affected products

• Mozilla Firefox: before 118 — fixed in 118
• Mozilla Firefox ESR: before 115.3 — fixed in 115.3
• Mozilla Thunderbird: before 115.3 — fixed in 115.3

How to fix

Upgrade to a fixed version: Mozilla Firefox 118; Mozilla Firefox ESR 115.3; Mozilla Thunderbird 115.3. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1848454
• https://www.mozilla.org/security/advisories/mfsa2023-41/
• https://www.mozilla.org/security/advisories/mfsa2023-42/
• https://www.mozilla.org/security/advisories/mfsa2023-43/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1848454
• https://www.mozilla.org/security/advisories/mfsa2023-41/
• https://www.mozilla.org/security/advisories/mfsa2023-42/
• https://www.mozilla.org/security/advisories/mfsa2023-43/

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