CVE-2026-54912

What it is

WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. Prior to 2.4.5, the two-pass fast interpreter loader in core/iwasm/interpreter/wasm_loader.c can make inconsistent constant-table decisions between the sizing pass and the emitting pass. After duplicate constants inflate the first pass beyond the constant-slot limit, wasm_loader_get_const_offset emits later constants inline, but the between-pass sort and deduplication reduces the table so the second pass can choose table references and cause reserve_block_ret to emit additional copy operands that were not included in code_compiled_peak_size. A crafted module can therefore make the second pass write partially attacker-controlled compiled-code data beyond the heap buffer allocated from the first pass's size calculation during wasm_runtime_load, before guest code executes. This can corrupt host heap metadata and deterministically crash the process, causing denial of service; further consequences depend on the host application's heap layout. Builds using WAMR_BUILD_FAST_INTERP=1 are affected; disabling the fast interpreter avoids the vulnerable loader. This issue is fixed in version 2.4.5.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-16 13:49 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-11-05 18:17 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-05 19:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 8.8 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-11-05 18:17 UTC

Last modified

2026-11-05 19:17 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-787 · Out-of-bounds write

Record status

Received

Attack profile CVSS 4.0 · 8.8

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

None

Confidentiality

Low

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-54912.md and follow it. Check whether this project is affected by CVE-2026-54912. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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