CVE-2025-58749: bytecodealliance wasm-micro-runtime · Untrusted Pointer Dereference
Affects bytecodealliance wasm-micro-runtimeSource CVE Database V5
Not known to be exploited · CVSS 2.1 Low : upgrade to 2.4.2 when convenient.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.4.2
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 16 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade bytecodealliance wasm-micro-runtime to 2.4.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| bytecodealliance wasm-micro-runtime | Affected
| Fixed in
|
AI-suggested
European organizations should prioritize upgrading WAMR to version 2.4.2 or later, where this vulnerability is fixed. For environments where immediate upgrade is not feasible, consider disabling LLVM-JIT mode and switching to FAST-JIT mode or other runtime tools that are not affected by this issue. Implement strict input validation and sandboxing for WebAssembly modules to prevent execution of untrusted or malformed Wasm code that could trigger the vulnerability. Monitoring runtime behavior for hangs or crashes can help detect exploitation attempts or accidental triggers. Additionally, integrate WAMR runtime updates into regular patch management cycles and conduct security testing of Wasm modules before deployment. For developers, avoid generating Wasm code that uses memory.fill instructions with large memory pointers in LLVM-JIT mode until the runtime is updated. Finally, maintain awareness of vendor advisories and community reports for any emerging exploits or related vulnerabilities.
Description
WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. In WAMR versions prior to 2.4.2, when running in LLVM-JIT mode, the runtime cannot exit normally when executing WebAssembly programs containing a memory.fill instruction where the first operand (memory address pointer) is greater than or equal to 2147483648 bytes (2GiB). This causes the runtime to hang in release builds or crash in debug builds due to accessing an invalid pointer. The issue does not occur in FAST-JIT mode or other runtime tools. This has been fixed in version 2.4.2.