PatchTheCVECVE-2026-119133: Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout
CVE-2026-119133 is a low-severity flaw (CVSS 2.6) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout that causes undefined behavior when modules contain an odd number of exception tags. A WebAssembly module with an odd tag count misaligns subsequent host fields in embedders with exceptions enabled, although no exploitation path is currently known.
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 2.6 (Low) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | Low |
| User interaction | Required |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-758 |
| Published | 2026-10-29 |
| Last modified | 2026-10-29 |
Last updated 2026-10-29 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- Vulners Bulletins: CVE-2026-119133 Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Misaligned VMContext via Exception Tags 2026-10-29
- Vulners Bulletins: CVE-2026-119133 Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Misaligned VMContext via Exception Tags 2026-10-29
- VulDB Recent Entries: CVE-2026-119133 | Bytecode Alliance Wasmtime up to 48.0.5/49.0.2 VMContext layout memory corruption 2026-10-29
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-119133?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-119133 being exploited?
CVE-2026-119133 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-119133 affect?
CVE-2026-119133 affects affected software. Severity is low (CVSS 2.6). Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout that causes undefined behavior when modules contain an odd number of exception tags. A WebAssembly module with an odd tag count m
How urgent is CVE-2026-119133?
Priority 9/100. No elevated risk signals yet.