Wasmtime vulnerable to segfault when using component resources
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Passive
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
Wasmtime is a runtime for WebAssembly. In versions from 38.0.0 to before 38.0.3, the implementation of component-model related host-to-wasm trampolines in Wasmtime contained a bug where it's possible to carefully craft a component, which when called in a specific way, would crash the host with a segfault or assert failure. Wasmtime 38.0.3 has been released and is patched to fix this issue. There are no workarounds.
Why it matters now
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 |
|---|---|---|---|---|---|
| bytecodealliance | wasmtime | 38.0.0 to before 38.0.3 | 38.0.3 | Patch available | CNA |
| — | wasmtime (crates.io) | 38.0.0 to before 38.0.3 | 38.0.3 | Patch available | GHSA-4h67-722j-5pmc |
- wasmtime Vendorbytecodealliance Affected 38.0.0 to before 38.0.3 Fixed in 38.0.3 Patch available CNA
- wasmtime (crates.io) Vendor— Affected 38.0.0 to before 38.0.3 Fixed in 38.0.3 Patch available GHSA-4h67-722j-5pmc
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:* | 38.0.0 to before 38.0.3 | Vulnerable | bytecodealliance |
- cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:* Versions 38.0.0 to before 38.0.3 Vulnerable ·bytecodealliance
Remediation
- Fix · CNA wasmtime (bytecodealliance) Fixed in 38.0.3
- Fix · GHSA-4h67-722j-5pmc wasmtime (crates.io) Fixed in 38.0.3 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Connectivity Link 1 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2025-62711
- 2026-10-03 Alias added: GHSA-4h67-722j-5pmc
References
Patch 3
More bytecodealliance Wasmtime vulnerabilities
- TI-2026-21632 Wasmtime is vulnerable to panic when dropping a `[Typed]Func::call_async` future CVSS 4.0MEDIUM 6.9
- TI-2023-11636 Guest-controlled out-of-bounds read/write on x86_64 in wasmtime CVSS 3.1CRITICAL 10.0
- TI-2022-18765 Wasmtime vulnerable to data leakage between instances in the pooling allocator CVSS 3.1HIGH 8.6
- TI-2022-08604 Use after free in Wasmtime CVSS 3.1CRITICAL 9.8
- TI-2022-18766 wasmtime_trap_code C API function has out of bounds write vulnerability CVSS 3.1CRITICAL 9.8
- TI-2026-27209 Wasmtime with Winch compiler backend on aarch64 may allow a sandbox-escaping memory access CVSS 4.0CRITICAL 9.0
Sources
- CVE-2025-62711 · CVE Program
- CVE-2025-62711 · NVD
- FIRST EPSS
- GHSA-4h67-722j-5pmc · GitHub Advisory Database · CC BY 4.0
- CVE-2025-62711 · 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