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TI-2026-82660 Aliases CVE-2026-119142GHSA-x9q9-vvfc-mrm5

Wasmtime host panic when call_async future is dropped

Priority LOW 26CWE-617Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Passive
Attack complexity
High
Attack requirements
Present
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 2 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-617.

Summary

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service flaw: dropping the Future returned by TypedFunc::call_async can panic the host. When the guest task has not started, cleanup searches only one location for work items and unwraps the resulting error, so embedders that cancel pending calls crash. The weakness is CWE-617 (Reachable Assertion). Red Hat rates it Moderate, and CVSS 4.0 scores it 5.9 (MEDIUM).

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service vulnerability where dropping the Future returned by TypedFunc::call_async can panic the host. When the guest task has not started, cleanup code searches only one location for work items and unwraps the resulting error, crashing embedders that cancel pending calls.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00254 17th percentileScored 2026-11-07
Fix Partial wasmtime (bytecodealliance): 48.0.6, 49.0.3Red Hat: 2 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

VendorProductAffected versionsFixed inStatusSource
bytecodealliancewasmtime46.0.0 to before 48.0.6; 49.0.0 to before 49.0.348.0.6, 49.0.3Patch availableCNA
  • wasmtime Vendorbytecodealliance Affected 46.0.0 to before 48.0.6; 49.0.0 to before 49.0.3 Fixed in 48.0.6, 49.0.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:*——bytecodealliance
  • cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:* Versions — — ·bytecodealliance

Remediation

Upgrade Wasmtime to 48.0.6 or 49.0.3, depending on the release line in use. Red Hat Connectivity Link 1 and Red Hat Enterprise Linux 10 have no fix available yet.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

  • Fix · CNA wasmtime (bytecodealliance) Fixed in 48.0.6, 49.0.3

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    bytecodealliance wasmtime 48.0.6, 49.0.3

    11 records Highest priority Priority LOW 11 LOW

    Other records, highest priority first

    • TI-2026-82659 Wasmtime realloc reentrancy lets Wasm modules crash the hostPriority LOW 37
    • TI-2026-82655 Stack overflow in Wasmtime via type registry lets guests crash hostPriority LOW 37
    • TI-2026-82649 Integer overflow in Wasmtime wasi-http lets guests crash the hostPriority LOW 36
    Show all 11 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Connectivity Link 1AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-29 Threatist record created from CVE-2026-119142
  2. 2026-10-29 Alias added: GHSA-x9q9-vvfc-mrm5
  3. 2026-10-29 CISA SSVC decision points changed
  4. 2026-10-29 Priority changed: MEDIUM → LOW
  5. 2026-10-30 Affected versions changed · Red Hat
  6. 2026-10-30 CVSS score added · Red Hat

References

Advisory 1

  • TI-2026-85541 WAMR fast interpreter loader heap overflow via constant deduplication mismatch CVSS 4.0HIGH 8.8
  • TI-2024-16741 An issue in bytecodealliance wasm-micro-runtime before v.b3f728c and fixed in commit… CVSS 3.1HIGH 8.8
  • TI-2024-22658 An out-of-bound memory read vulnerability was discovered in Bytecode Alliance… CVSS 3.1HIGH 7.5
  • TI-2024-18300 wasm-micro-runtime (aka WebAssembly Micro Runtime or WAMR) 06df58f is vulnerable to NULL… CVSS 3.1HIGH 7.5
  • TI-2023-26034 An heap overflow vulnerability was discovered in Bytecode alliance wasm-micro-runtime… CVSS 3.1HIGH 7.5
  • TI-2025-33969 WebAssembly Micro Runtime's `--addr-pool` option allows all IPv4 addresses when subnet mask is not specified CVSS 4.0MEDIUM 6.9
See all 97 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences