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Bump serialize-javascript to 7.0.5 (CVE-2026-34043)#129

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Bump serialize-javascript to 7.0.5 (CVE-2026-34043)#129
Copilot wants to merge 2 commits intomainfrom
copilot/fix-cpu-exhaustion-dos-vulnerability

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Copilot AI commented Apr 2, 2026

serialize-javascript@6.0.2 is vulnerable to CPU exhaustion DoS via crafted array-like objects (GHSA-qj8w-gfj5-8c6v). Fixed in 7.0.5 by replacing instanceof Array with Array.isArray().

Changes

  • .github/scripts/package.json — added overrides to pin serialize-javascript to 7.0.5
  • .github/scripts/package-lock.json — regenerated; serialize-javascript now resolves to 7.0.5
"overrides": {
    "serialize-javascript": "7.0.5"
}

Reachability

serialize-javascript is a transitive dependency of mocha only. It is never imported or called directly in application or test code — no user-controlled data is ever passed to serialize(). Risk is low; update resolves the scanner alert.

Original prompt

This section details the Dependabot vulnerability alert you should resolve

<alert_title>Serialize JavaScript has CPU Exhaustion Denial of Service via crafted array-like objects</alert_title>
<alert_description>### 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 v7.0.5 as soon as possible.

Acknowledgements

Serialize JavaScript thanks Tomer Aberbach (@TomerAberbach) for discovering and privately disclosing this issue.</alert_description>

moderate
GHSA-qj8w-gfj5-8c6v, CVE-2026-34043
serialize-javascript
npm
<vulnerable_versions>6.0.2</vulnerable_versions>
<patched_version>7.0.5</patched_version>
<manifest_path>.github/scripts/package-lock.json</manifest_path>

https://github.com/yahoo/serialize-javascript/security/advisories/GHSA-qj8w-gfj5-8c6v https://github.com/yahoo/serialize-javascript/commit/f147e90269b58bb6e539cfdf3d0e20d6ad14204b https://github.com/yahoo/serialize-javascript/releases/tag/v7.0.5 https://nvd.nist.gov/vuln/detail/CVE-2026-34043 https://github.com/advisories/GHSA-qj8w-gfj5-8c6v

<task_instructions>Resolve this alert by updating the affected package to a non-vulnerable version. Prefer the lowest non-vulnerable version (see the patched_version field above) over the latest to minimize breaking changes. Include a Reachability Assessment section in the PR description. Review the alert_description field to understand which APIs, features, or configurations are affected, then search the codebase for usage of those specific items. If the vulnerable code path is reachable, explain how (which files, APIs, or call sites use the affected functionality) and note that the codebase is actively exposed to this vulnerability. If the vulnerable code path is not reachable, explain why (e.g. the affected API is never called, the vulnerable configuration is not used) and note that the update is primarily to satisfy vulnerability scanners rather than to address an active risk. If the advisory is too vague to determine reachability (e.g. 'improper input validation' with no specific API named), state that reachability could not be determined and explain why. Include a confidence level in the reachability assessment (e.g. high confidence if the advisory names a specific API and you confirmed it is or is not called, low confidence if the usage is indirect and hard to trace). If no patched version is available, check the alert_description field for a Workarounds section — the advisory may describe configuration changes or usage patterns that mitigate the vulnerability without a version update. If a workaround is available, apply it and leave a code comment referencing the advisory identifier explaining it is a temporary mitigation. If neither a patch nor a workaround is available, explain in the PR description why the alert cannot be resolved automatically so a human reviewer can take over. Inspect the repository to determine which package manager is used (e.g. lock files, config files, build scripts) and use that tooling to perform the update — do not edit lock files directly. If the version constraint in the manifest (e.g. package.json, Gemfile, pyproject.toml) caps the version below the fix, update the constraint first. For transitive dependencies, determine whether it is simpler to update the direct dependency that pulls in the vulnerable package or to update the transitive dependency directly, and choose the least disruptive approach. If upgrading to fix the vulnerability forces ...

Copilot AI changed the title [WIP] Fix CPU exhaustion denial of service vulnerability in serialize-javascript Bump serialize-javascript to 7.0.5 (CVE-2026-34043) Apr 2, 2026
Copilot AI requested a review from lindluni April 2, 2026 13:28
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