VulnerabilityPublished 29 Jul 2025

CVE-2025-54126: bytecodealliance wasm-micro-runtime · Resource Exposure

Affects bytecodealliance wasm-micro-runtimeSource CVE Database V5

Not known to be exploited · CVSS 6.9 Medium : upgrade to 2.4.1 when convenient.

Data as of 26 Oct 2026, 12:29 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.4.1

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: Low
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Subsequent System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Jul 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade bytecodealliance/wasm-micro-runtime to 2.4.1.

Affected software

Product	Affected	Fixed in
GitHubbytecodealliance/wasm-micro-runtime`pkg:github/bytecodealliance/wasm-micro-runtime`Other threats	Affected <2.4.1	Fixed in 2.4.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should immediately audit their deployments of wasm-micro-runtime, specifically the iwasm component, to identify versions below 2.4.1. They should upgrade all affected instances to version 2.4.1 or later, where the vulnerability is fixed. Until upgrades can be performed, organizations should avoid using the --addr-pool parameter without explicitly specifying a subnet mask to ensure proper IP filtering. Network-level controls such as firewall rules and intrusion prevention systems should be configured to restrict access to the affected services to trusted IP ranges. Additionally, organizations should implement monitoring and logging of access attempts to detect any unauthorized connection attempts. Security teams should review configuration management and deployment pipelines to prevent insecure defaults from being propagated. Finally, penetration testing and vulnerability scanning should include checks for this specific misconfiguration to proactively identify exposure.

Description

The WebAssembly Micro Runtime's (WAMR) iwasm package is the executable binary built with WAMR VMcore which supports WebAssembly System Interface (WASI) and command line interface. In versions 2.4.0 and below, iwasm uses --addr-pool with an IPv4 address that lacks a subnet mask, allowing the system to accept all IP addresses. This can unintentionally expose the service to all incoming connections and bypass intended access restrictions. Services relying on --addr-pool for restricting access by IP may unintentionally become open to all external connections. This may lead to unauthorized access in production deployments, especially when users assume that specifying an IP without a subnet mask implies a default secure configuration. This is fixed in version 2.4.1.

Impact

For European organizations using wasm-micro-runtime versions prior to 2.4.1, this vulnerability could lead to unauthorized external access to services that were presumed to be restricted by IP address. This exposure risks leakage of sensitive data or unauthorized use of the service, potentially leading to further exploitation or lateral movement within networks. Given the increasing adoption of WebAssembly runtimes in cloud-native, edge computing, and IoT environments, the vulnerability could impact sectors such as finance, healthcare, telecommunications, and critical infrastructure in Europe. Unauthorized access could undermine confidentiality and trust, and in regulated industries, may lead to compliance violations (e.g., GDPR) if personal data is exposed. The lack of requirement for authentication or user interaction makes exploitation easier for remote attackers scanning for vulnerable endpoints. However, the limited impact on integrity and availability reduces the likelihood of destructive attacks but does not eliminate the risk of data exposure or misuse.

CWE-668Exposure of Resource to Wrong Sphere (opens in a new tab)
Class weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
OWASP Cheat Sheets
Authorization (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Aug 2025, 01:06 UTC

WeaknessesCWE-668

Technical details

References

Community reviews

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