TI-2026-82661 Aliases CVE-2026-119143 GHSA-368p-492j-h227

Panic in Wasmtime lets guest code crash WASIp3 embedders

LOW 26CWE-129Published 2026-10-29 · Updated 2026-11-04

Key facts

Attack vector: Network
Privileges required: Low
User interaction: Passive
Attack complexity: Low
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-129 and the CVSS impact.

Summary

Wasmtime from 46.0.0 before 48.0.6 and from 49.0.0 before 49.0.3 contains a denial of service flaw. Zero-length component model stream reads or writes use unvalidated addresses, which is an improper validation of array index (CWE-129). Malicious guest code can trigger a panic in Direct{Source,Destination}::remaining that crashes WASIp3 embedders.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

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 that allows guest code to trigger a host panic through out-of-bounds zero-length stream operations. Malicious guests can perform zero-length component model stream reads or writes with unvalidated addresses, causing Direct{Source,Destination}::remaining to panic and crash WASIp3 embedders.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00212 11th 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

Vendor	Product	Affected versions	Fixed in	Status	Source
bytecodealliance	wasmtime	46.0.0 to before 48.0.6; 49.0.0 to before 49.0.3	48.0.6, 49.0.3	Patch available	CNA

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.

CPE	Versions	Role	Vendor
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. Red Hat lists Red Hat Connectivity Link 1 and Red Hat Enterprise Linux 10 as affected, with no fix available.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

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 · 2026-10-29
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 →

Product	Status	Plan or fix
Red Hat Connectivity Link 1	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred

Timeline

2026-10-29 Threatist record created from CVE-2026-119143
2026-10-29 Alias added: GHSA-368p-492j-h227
2026-10-30 Affected versions changed · Red Hat
2026-10-30 CVSS score added · Red Hat
2026-10-31 Priority changed: MEDIUM → LOW
2026-11-04 CISA SSVC decision points changed

References

Advisory 1

GitHub Security Advisory (GHSA-93g3-36p8-x2gc)

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