Red Hat CVE-2026-34043
MEDIUMSeverity by source
AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from GitHub Advisory.
CVSS VectorGitHub Advisory
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
3Blast Radius
ecosystem impact- 1 npm packages depend on serialize-javascript (1 direct, 0 indirect)
Ecosystem-wide dependent count for version 5.0.0.
DescriptionGitHub Advisory
Impact
What kind of vulnerability is it?
It is a Denial of Service (DoS) vulnerability caused by CPU exhaustion. When serializing a specially crafted "array-like" object (an object that inherits from Array.prototype but has a very large length property), the process enters an intensive loop that consumes 100% CPU and hangs indefinitely.
Who is impacted?
Applications that use serialize-javascript to serialize untrusted or user-controlled objects are at risk. While direct exploitation is difficult, it becomes a high-priority threat if the application is also vulnerable to Prototype Pollution or handles untrusted data via YAML Deserialization, as these could be used to inject the malicious object.
Patches
Has the problem been patched?
Yes, the issue has been patched by replacing instanceof Array checks with Array.isArray() and using Object.keys() for sparse array detection.
What versions should users upgrade to?
Users should upgrade to v7.0.5 or later.
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
There is no direct code-level workaround within the library itself. However, users can mitigate the risk by:
- Validating and sanitizing all input before passing it to the
serialize()function. - Ensuring the environment is protected against Prototype Pollution.
- Upgrading to
v7.0.5as soon as possible.
Acknowledgements
Serialize JavaScript thanks Tomer Aberbach (@TomerAberbach) for discovering and privately disclosing this issue.
AnalysisAI
The serialize-javascript npm library versions prior to 7.0.5 contain a CPU exhaustion denial-of-service vulnerability triggered when processing specially crafted array-like objects with artificially large length properties, causing the serialization process to hang indefinitely and consume 100% CPU. The vulnerability affects npm package serialize-javascript (pkg:npm/serialize-javascript) and impacts applications that serialize untrusted or user-controlled objects, particularly those also vulnerable to prototype pollution or YAML deserialization attacks that could inject malicious payloads. No public exploit code has been identified, but the attack vector is network-accessible with high complexity, posing a moderate real-world threat in supply-chain and backend service contexts.
Technical ContextAI
The vulnerability exists in the serialize-javascript npm library, identified via CPE pkg:npm/serialize-javascript. The root cause is classified under CWE-400 (Uncontrolled Resource Consumption), stemming from the library's use of instanceof Array checks that can be bypassed by objects inheriting from Array.prototype with maliciously large length properties. When such objects are serialized, the library enters an intensive loop attempting to process array indices up to the artificial length value, exhausting CPU cycles. The patch, committed to the Yahoo serialize-javascript repository and released in version 7.0.5, replaces instanceof Array checks with the more robust Array.isArray() method and uses Object.keys() for sparse array detection, preventing the bypass mechanism and ensuring bounded iteration.
RemediationAI
Upgrade serialize-javascript to version 7.0.5 or later immediately via npm update. Consult the vendor security advisory at https://github.com/yahoo/serialize-javascript/security/advisories/GHSA-qj8w-gfj5-8c6v for confirmation. Until patching is feasible, implement input validation and sanitization on all untrusted data before passing it to the serialize() function, and audit the application for prototype pollution and unsafe YAML deserialization patterns that could be chained to inject malicious objects. In high-risk environments, consider rate-limiting or timeout enforcement on serialization operations to mitigate CPU exhaustion attacks.
Same weakness CWE-400 – Uncontrolled Resource Consumption
View allSame technique Denial Of Service
View allVendor StatusVendor
SUSE
Severity: Medium| Product | Status |
|---|---|
| SUSE Liberty Linux 8 | Fixed |
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External POC / Exploit Code
Leaving vuln.today