Vulnerability Description
On 64-bit CPUs, when the JIT compiles WASM i32 return values they can pick up bits from left over memory. This can potentially cause them to be treated as a different type. This vulnerability was fixed in Firefox 136, Firefox ESR 115.21, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 115.21.0 |
| Mozilla | Thunderbird | < 128.8 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1946004Issue Tracking
- https://www.mozilla.org/security/advisories/mfsa2025-14/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-15/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-16/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-17/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2025-18/Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2025/03/msg00006.html
FAQ
What is CVE-2025-1933?
CVE-2025-1933 is a vulnerability with a CVSS score of 7.6 (HIGH). On 64-bit CPUs, when the JIT compiles WASM i32 return values they can pick up bits from left over memory. This can potentially cause them to be treated as a different type. This vulnerability was fixe...
How severe is CVE-2025-1933?
CVE-2025-1933 has been rated HIGH with a CVSS base score of 7.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-1933?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.