SB2026080123 - Multiple vulnerabilities in wasm-micro-runtime

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Main Vulnerability Database SB2026080123

SB2026080123 - Multiple vulnerabilities in wasm-micro-runtime

Published: August 1, 2026 Updated: August 5, 2026

Security Bulletin ID SB2026080123
CSH Severity
High
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

High 33% Medium 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Heap-based buffer overflow (CVE-ID: CVE-2026-54914)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in wasmtime_ssp_poll_oneoff() when processing a crafted guest Wasm module that invokes WASI poll_oneoff with multiple subscriptions. A remote attacker can supply a crafted Wasm module to execute arbitrary code.

The issue can also cause a denial of service and breaks the runtime's sandbox isolation guarantee. WASI poll_oneoff is enabled by default, and no user interaction is required.


2) Use of Uninitialized Variable (CVE-ID: CVE-2026-54913)

CWE-ID: CWE-457 - Use of Uninitialized Variable

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to disclose host stack memory to the WebAssembly guest.

The vulnerability exists due to use of an uninitialized variable in load_init_expr in core/iwasm/interpreter/wasm_loader.c when parsing crafted WebAssembly global initialization expressions using ref.null with an invalid wide heap type. A remote attacker can supply a specially crafted WebAssembly module to disclose host stack memory to the WebAssembly guest.

Only the classic or fast interpreter loader is affected in builds with WASM_ENABLE_GC=0, and wider globals can increase the amount of leaked data.


3) Out-of-bounds write (CVE-ID: CVE-2026-54912)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to out-of-bounds write in the fast interpreter loader in wasm_loader.c when loading a crafted WebAssembly module via wasm_runtime_load(). A remote attacker can supply a crafted WebAssembly module to cause a denial of service.

The issue occurs during module loading before any wasm code is executed, and the out-of-bounds write contains partially attacker-controlled data.


Remediation

Install update from vendor's website.

References