JIT corruption of WASM i32 return values on 64-bit CPUs
Priority LOW 33Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · High
- Fix status
- Partial Red Hat: 14 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00319 24th percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 115.21, 128.8, 136Thunderbird (Mozilla): 128.8, 136Red Hat: 10 advisoriesRed Hat: 14 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Firefox | — | 115.21, 128.8, 136 | Patch available | CNA |
| Mozilla | Thunderbird | — | 128.8, 136 | Patch available | CNA |
- Firefox VendorMozilla Affected — Fixed in 115.21, 128.8, 136 Patch available CNA
- Thunderbird VendorMozilla Affected — Fixed in 128.8, 136 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* | before 115.21.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 136.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* | 116.0 to before 128.8.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 128.8; 129.0 to before 136.0 | Vulnerable | Mozilla |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* Versions before 115.21.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 136.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* Versions 116.0 to before 128.8.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 128.8; 129.0 to before 136.0 Vulnerable ·Mozilla
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 115.21, 128.8, 136
- Fix · CNA Thunderbird (Mozilla) Fixed in 128.8, 136
Red Hat 10 advisories
- RHSA-2025:2708 Released 2025-03-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox-128.8.0-1.el8_2
- RHSA-2025:2699 Released 2025-03-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Server (v. 7 ELS) firefox-128.8.0-1.el7_9
- RHSA-2025:2486 Released 2025-03-10 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v.8.8) firefox-128.8.0-1.el8_8
Show 7 more Red Hat advisories
- RHSA-2025:2484 Released 2025-03-10 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-128.8.0-1.el8_4
- Red Hat Enterprise Linux AppStream E4S (v.8.4) firefox-128.8.0-1.el8_4
- Red Hat Enterprise Linux AppStream TUS (v.8.4) firefox-128.8.0-1.el8_4
- RHSA-2025:2485 Released 2025-03-10 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-128.8.0-1.el8_6
- Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox-128.8.0-1.el8_6
- Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox-128.8.0-1.el8_6
- RHSA-2025:2479 Released 2025-03-10 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox-128.8.0-1.el9_4, firefox-x11-128.8.0-1.el9_4
- RHSA-2025:2480 Released 2025-03-10 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v.9.2) firefox-128.8.0-1.el9_2, firefox-x11-128.8.0-1.el9_2
- RHSA-2025:2481 Released 2025-03-10 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox-128.8.0-1.el9_0
- RHSA-2025:2452 Released 2025-03-06 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-128.8.0-1.el8_10
- RHSA-2025:2359 Released 2025-03-05 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 9) firefox-128.8.0-1.el9_5, firefox-x11-128.8.0-1.el9_5
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2025:2452 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:2359 |
| Red Hat Enterprise Linux AppStream AUS (v. 8.2) | Fixed | RHSA-2025:2708 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2025:2484 |
| Red Hat Enterprise Linux AppStream AUS (v.8.6) | Fixed | RHSA-2025:2485 |
| Red Hat Enterprise Linux AppStream E4S (v.8.4) | Fixed | RHSA-2025:2484 |
| Red Hat Enterprise Linux AppStream E4S (v.8.6) | Fixed | RHSA-2025:2485 |
| Red Hat Enterprise Linux AppStream E4S (v.9.0) | Fixed | RHSA-2025:2481 |
| Red Hat Enterprise Linux AppStream EUS (v.8.8) | Fixed | RHSA-2025:2486 |
| Red Hat Enterprise Linux AppStream EUS (v.9.2) | Fixed | RHSA-2025:2480 |
| Red Hat Enterprise Linux AppStream EUS (v.9.4) | Fixed | RHSA-2025:2479 |
| Red Hat Enterprise Linux AppStream TUS (v.8.4) | Fixed | RHSA-2025:2484 |
| Red Hat Enterprise Linux AppStream TUS (v.8.6) | Fixed | RHSA-2025:2485 |
| Red Hat Enterprise Linux Server (v. 7 ELS) | Fixed | RHSA-2025:2699 |
Timeline
- 2026-10-02 Threatist record created from CVE-2025-1933
- 2026-10-03 Alias added: GHSA-r84f-4wj3-r6vx
References
Advisory 5
More Mozilla Firefox vulnerabilities
- TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
- TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
- TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
- TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2025-1933 · CVE Program
- CVE-2025-1933 · NVD
- FIRST EPSS
- GHSA-r84f-4wj3-r6vx · GitHub Advisory Database · CC BY 4.0
- CVE-2025-1933 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences