VulnerabilityModified
CVE-2025-1933
This vulnerability was fixed in Firefox 136, Firefox ESR 115.21, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.
HIGH 7.6EPSS 0.31%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
- EPSS
- 0.31% probability · 24th percentile
- CISA KEV
- Not listed
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.