NULL pointer dereference in Mozilla Firefox
CVE-2025-8033
The JavaScript engine did not handle closed generators correctly and it was possible to resume them leading to a nullptr deref. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.
EPSS: 0.003 (27.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
Affected products
- Mozilla Firefox — versions 115.26, 128.13, 140.1
- Mozilla Thunderbird — versions 128.13, 140.1, 141
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security@mozilla.org (Permissions Required)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-8033?
- CVE-2025-8033 is a medium-severity vulnerability in Mozilla Firefox, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2025-07-22.
- How severe is CVE-2025-8033?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2025-8033 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.