CVE-2025-6274VulnerabilityPublished 19 Jun 2025Updated 23 Jun 2025

CVE-2025-6274: WebAssembly wabt · Resource Consumption

Affects WebAssembly wabtSource CVE Database V5

Not known to be exploited · CVSS 4.8 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

4.8Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

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

Threat metrics

Exploit Maturity: POC

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

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
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: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable 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.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Jun 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 2026-10-25.

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 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

Affected software

Product	Affected	Fixed in
GitHubwebassembly/wabt`pkg:github/webassembly/wabt`Other threats	Affected =1.0.0 =1.0.1 =1.0.2 =1.0.3 =1.0.4 =1.0.5 =1.0.6 =1.0.7 =1.0.8 =1.0.9 =1.0.10 =1.0.11 =1.0.12 =1.0.13 =1.0.14 =1.0.15 =1.0.16 =1.0.17 =1.0.18 =1.0.19 =1.0.20 =1.0.21 =1.0.22 =1.0.23 =1.0.24 =1.0.25 =1.0.26 =1.0.27 =1.0.28 =1.0.29 =1.0.30 =1.0.31 =1.0.32 =1.0.33 =1.0.34 =1.0.35 =1.0.36 =1.0.37	Fixed in–

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

AI-suggested

1. Restrict local access to systems running wabt to trusted users only, minimizing the risk of local exploitation. 2. Monitor resource consumption on developer and build machines when processing WebAssembly binaries with wabt to detect abnormal spikes indicative of exploitation attempts. 3. Isolate build environments and use containerization or virtual machines to limit the impact of potential resource exhaustion. 4. Stay updated with the wabt project for official patches or updates addressing this vulnerability and apply them promptly once available. 5. Implement strict code review and validation of WebAssembly binaries processed by wabt to avoid malformed inputs that could trigger the vulnerability. 6. Consider alternative WebAssembly tools or updated versions if they provide improved resilience against resource consumption issues. 7. Educate developers and system administrators about the vulnerability and the importance of limiting local access and monitoring resource usage.

Description

A vulnerability was found in WebAssembly wabt up to 1.0.37. It has been classified as problematic. Affected is the function OnDataCount of the file src/interp/binary-reader-interp.cc. The manipulation leads to resource consumption. Attacking locally is a requirement. The exploit has been disclosed to the public and may be used. A similar issue reported during the same timeframe was disputed by the code maintainer because it might not affect "real world wasm programs". Therefore, this entry might get disputed as well in the future.

Impact

For European organizations, the impact of CVE-2025-6274 is primarily related to development and build environments that utilize the wabt tool for WebAssembly binary processing. Since wabt is a developer tool rather than a runtime environment, the direct risk to production systems is limited. However, organizations heavily invested in WebAssembly development, such as software vendors, cloud service providers offering WebAssembly execution environments, and research institutions, could experience denial-of-service conditions on developer machines or build servers if exploited locally. This could lead to delays in development cycles or resource exhaustion on critical build infrastructure. The vulnerability does not pose a direct threat to confidentiality or data integrity but could indirectly affect availability of development resources. Given the local attack vector requirement, the threat is more relevant in environments where multiple users have local access or where attacker footholds have already been established. European organizations with strict internal access controls and segmented development environments will be less exposed. The lack of known exploits in the wild and the disputed practical impact reduce the immediate urgency but do not eliminate the need for caution in sensitive or high-availability development contexts.

Summary

CVE-2025-6274 is a medium-severity vulnerability affecting the WebAssembly Binary Toolkit (wabt) versions 1.0.0 through 1.0.37. The vulnerability resides in the OnDataCount function within the src/interp/binary-reader-interp.cc source file. It is characterized as a resource consumption issue, which can be triggered by manipulating input data to cause excessive resource usage during WebAssembly binary interpretation. The vulnerability requires local access with low privileges (local attack vector with low complexity) and does not require user interaction or authentication beyond local access. The CVSS 4.0 base score is 4.8, reflecting a medium impact primarily on availability due to resource exhaustion. Although an exploit has been publicly disclosed, there are no known exploits currently observed in the wild. Additionally, the maintainer has disputed a similar issue, suggesting that the practical impact on real-world WebAssembly programs may be limited, which could also apply to this vulnerability. The vulnerability does not affect confidentiality or integrity, and the scope is limited to the wabt tool, which is primarily used by developers and toolchains working with WebAssembly binaries rather than end-user applications. No official patches have been linked yet, so mitigation currently relies on limiting local access and monitoring resource usage during wabt operations.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 19 Jun 2025, 19:32 UTC

Technical details

References

Community reviews

Related threats