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TI-2026-82648 Aliases CVE-2026-119130GHSA-pr9x-c379-2x4g

Wasmtime HTTP target smuggling lets guests reach disallowed hosts

Priority LOW 11CWE-20Published · Updated

Key facts

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

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

Summary

Wasmtime before 36.0.18, from 37.0.0 before 48.0.6, and from 49.0.0 before 49.0.3 does not verify that set-path-with-query values in wasmtime-wasi-http are paths. Absolute-form URLs are written verbatim as the HTTP/1.1 request target while the connection uses the allowed authority, a flaw caused by improper input validation (CWE-20). A malicious guest can supply an absolute URL that a forward proxy or gateway at that authority honors, reaching hosts that embedder filtering policies disallow.

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

Description from the CNA

Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 does not verify that set-path-with-query values in wasmtime-wasi-http are paths, so absolute-form URLs are written verbatim as the HTTP/1.1 request target while the connection uses the allowed authority. A malicious guest can supply an absolute URL that a forward proxy or gateway at that authority honors, reaching hosts disallowed by embedder filtering policies.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00236 14th percentileScored 2026-11-07
Fix Fixed wasmtime (bytecodealliance): 36.0.18, 48.0.6, 49.0.3

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
bytecodealliancewasmtimebefore 36.0.18; 37.0.0 to before 48.0.6; 49.0.0 to before 49.0.336.0.18, 48.0.6, 49.0.3Patch availableCNA
  • wasmtime Vendorbytecodealliance Affected before 36.0.18; 37.0.0 to before 48.0.6; 49.0.0 to before 49.0.3 Fixed in 36.0.18, 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 36.0.18, 48.0.6, or 49.0.3, depending on the release line in use.

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

  • Fix · CNA wasmtime (bytecodealliance) Fixed in 36.0.18, 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 36.0.18, 48.0.6, 49.0.3

    2 records Highest priority Priority LOW 2 LOW

    Other records, highest priority first

    • TI-2026-82652 Unbounded memory growth in Wasmtime via resource handlesPriority LOW 29
    Show all 2 records →

Timeline

  1. 2026-10-29 Threatist record created from CVE-2026-119130
  2. 2026-10-29 Alias added: GHSA-pr9x-c379-2x4g
  3. 2026-10-29 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