Read the docs
TI-2026-85543 Aliases CVE-2026-54914

Heap buffer overflow in WAMR WASI poll_oneoff output buffer

Priority LOW 36CWE-122Published · Updated

Key facts

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

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

Summary

WebAssembly Micro Runtime (WAMR) before 2.4.5 has a heap-based buffer overflow in its WASI poll_oneoff implementation. The output pointer is validated for only one event, while the sandboxed poll_oneoff path can write as many events as the guest-controlled nsubscriptions value. A crafted guest module can cause writes past the validated Wasm linear memory into adjacent host heap memory, CWE-122. An attacker who can run a crafted WebAssembly module can reliably crash the host process, and further confidentiality or integrity impact depends on heap layout.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Description from the CNA

WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. Prior to 2.4.5, wasi_poll_oneoff in core/iwasm/libraries/libc-wasi/libc_wasi_wrapper.c validates the output pointer for only one wasi_event_t, while wasmtime_ssp_poll_oneoff in core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/posix.c can write as many events as the guest-controlled nsubscriptions value. A crafted guest module can provide multiple subscriptions that produce events while positioning an output region large enough for only one event, causing a later out[nevents] write to cross the validated Wasm linear-memory boundary into adjacent host heap memory. The overwrite contains partly attacker-controlled event data and can reliably crash the host process, with further confidentiality or integrity consequences depending on heap layout. This issue is fixed in version 2.4.5.

Why it matters now

EPSS 0.00399 34th percentileScored 2026-11-07
Fix Fixed wasm-micro-runtime (bytecodealliance): 2.4.5

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
bytecodealliancewasm-micro-runtimebefore 2.4.52.4.5Patch availableCNA
  • wasm-micro-runtime Vendorbytecodealliance Affected before 2.4.5 Fixed in 2.4.5 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:webassembly_micro_runtime:*:*:*:*:*:*:*:*——bytecodealliance
  • cpe:2.3:a:bytecodealliance:webassembly_micro_runtime:*:*:*:*:*:*:*:* Versions — — ·bytecodealliance

Remediation

Upgrade bytecodealliance wasm-micro-runtime to version 2.4.5, which fixes this issue.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

  • Fix · CNA wasm-micro-runtime (bytecodealliance) Fixed in 2.4.5

Timeline

  1. 2026-11-05 Threatist record created from CVE-2026-54914
  2. 2026-11-07 Priority changed: MEDIUM → LOW

References

Other 4

  • 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