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TI-2026-82654 Aliases CVE-2026-119136GHSA-xp2q-mv29-hr2p

Wasmtime Async-Entrypoint Enforcement Bypass

Priority LOW 26CWE-1265Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Passive
Attack complexity
High
Attack requirements
Present
Impact type
—
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.

Summary

Wasmtime from 42.0.0 before 48.0.6 and from 49.0.0 before 49.0.3 contains insufficient checks in Store when it mixes async-style and sync-style WebAssembly calls, a case of unintended reentrant invocation (CWE-1265). An attacker with low privileges who can get a user to interact with the affected embedding can cause runtime panics or unsound cross-thread movement of !Send host variables. Embedders that re-enter WebAssembly through sync APIs from asynchronously called host functions are exposed.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

Description from the CNA

Wasmtime 42.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains insufficient checks in Store when mixing async-style and sync-style WebAssembly calls. Embedders re-entering WebAssembly via sync APIs from host functions called asynchronously can trigger runtime panics or unsound cross-thread movement of !Send host variables.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00208 10th 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
bytecodealliancewasmtime42.0.0 to before 48.0.6; 49.0.0 to before 49.0.348.0.6, 49.0.3Patch availableCNA
  • wasmtime Vendorbytecodealliance Affected 42.0.0 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 for the 48 line or to 49.0.3 for the 49 line. Red Hat's plan for Red Hat Connectivity Link 1 and Red Hat Enterprise Linux 10 is none available.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

  • 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-2026-119136
  2. 2026-10-29 Alias added: GHSA-xp2q-mv29-hr2p
  3. 2026-10-30 Affected versions changed · Red Hat
  4. 2026-10-30 CVSS score added · Red Hat
  5. 2026-10-31 Priority changed: MEDIUM → LOW
  6. 2026-11-03 CISA SSVC decision points changed

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