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TI-2026-82649 Aliases CVE-2026-119131GHSA-9vvr-fpgq-p9gc

Integer overflow in Wasmtime wasi-http lets guests crash the host

Priority LOW 36CWE-190Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

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 in wasmtime-wasi-http. A guest that sends a request URL longer than 65535 bytes with a '?' after that point overflows a u16 index (CWE-190), which makes the host panic. An unauthenticated remote attacker can crash the host with a low-complexity request, and the impact is limited to availability.

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 in wasmtime-wasi-http that lets guests crash the host by sending long request URLs. Guests can use set-path-with-query with a '?' after byte 65535, overflowing a u16 index in the http crate and triggering a host panic.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00304 23rd percentileScored 2026-11-07
Fix Fixed wasmtime (bytecodealliance): 48.0.6, 49.0.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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 version 48.0.6 for the 48.x line or to version 49.0.3 for the 49.x line. The sources do not list a vendor advisory identifier for this fix.

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 ·

    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-2026-82661 Panic in Wasmtime lets guest code crash WASIp3 embeddersPriority LOW 26
    Show all 11 records →

Timeline

  1. 2026-10-29 Threatist record created from CVE-2026-119131
  2. 2026-10-29 Alias added: GHSA-9vvr-fpgq-p9gc
  3. 2026-10-31 Priority changed: MEDIUM → LOW
  4. 2026-11-04 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