{"answers":{"affected":"2 open source packages ship an affected version, including @theecryptochad/merge-guard.","exploited":"There is no known exploitation of GHSA-mhwj-73qx-jqxm in the wild and no public exploit code.","fix":"Upgrade @theecryptochad/merge-guard to 1.0.1 or later.","what":"GHSA-mhwj-73qx-jqxm is an unsafe deserialization vulnerability in @theecryptochad/merge-guard, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for GHSA-mhwj-73qx-jqxm and fix it if it is affected.\n\nWhat it is: GHSA-mhwj-73qx-jqxm is an unsafe deserialization vulnerability in @theecryptochad/merge-guard, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of GHSA-mhwj-73qx-jqxm in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- @theecryptochad/merge-guard (npm): affected all versions; fixed in 1.0.1\n- @theecryptochad/merge-guard (npm): affected all versions; fixed in 1.0.1\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/GHSA-mhwj-73qx-jqxm/ (Markdown: https://insights.sbomify.com/GHSA-mhwj-73qx-jqxm/index.md)","id":"GHSA-mhwj-73qx-jqxm","markdown":"https://insights.sbomify.com/GHSA-mhwj-73qx-jqxm/index.md","name":"GHSA-mhwj-73qx-jqxm","record":{"aliases":[],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["privilege_escalation","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Node.js merge library","requires_auth":"none","summary":"Prototype pollution in deepMerge allows attackers to inject properties into Object.prototype, leading to privilege escalation or logic bypass.","user_interaction":"not_required","vuln_class":"deserialization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"## Summary\n\n`@theecryptochad/merge-guard` versions prior to 1.0.1 are vulnerable to Prototype Pollution via the `deepMerge()` function. An attacker who controls the source object can inject `__proto__` keys that mutate `Object.prototype`, affecting all objects in the Node.js runtime.\n\n## Details\n\nThe `deepMerge()` function recursively merges two objects without sanitizing reserved property keys (`__proto__`, `constructor`, `prototype`). When a source object contains a `__proto__` key, its value is assigned to `target.__proto__`, which JavaScript engines interpret as a write to `Object.prototype`.\n\n## Proof of Concept\n\n```js\nconst { deepMerge } = require('@theecryptochad/merge-guard');\nconst payload = JSON.parse('{\"__proto__\":{\"isAdmin\":true}}');\ndeepMerge({}, payload);\nconsole.log({}.isAdmin); // true — Object.prototype is polluted\n```\n\n## Impact\n\nAny application using `deepMerge()` with untrusted input (e.g. user-supplied JSON from HTTP requests, WebSocket messages, or config files) is vulnerable. An attacker can inject arbitrary properties onto `Object.prototype`, enabling privilege escalation, application logic bypass, and property injection.\n\n## Remediation\n\nUpgrade to `@theecryptochad/merge-guard \u003e= 1.0.1`, which adds an explicit blocklist:\n\n```js\nconst BLOCKED = new Set(['__proto__', 'constructor', 'prototype']);\nif (BLOCKED.has(key)) continue;\n```\n\n## References\n- [CWE-1321: Improper Neutralization of Special Elements in Object Keys](https://cwe.mitre.org/data/definitions/1321.html)\n- [OWASP: Prototype Pollution](https://owasp.org/www-community/attacks/Prototype_Pollution)\n- [Fix commit](https://github.com/TheeCryptoChad/merge-guard/releases/tag/v1.0.1)","ecosystems":["npm"],"exploits":{"exploitdb":null,"first_seen":null,"github_poc":null,"max_poc_stars":null,"metasploit":null,"nuclei":null,"refs":[],"tier":null},"has_fix":true,"headline":"@theecryptochad/merge-guard has Prototype Pollution in its deepMerge() function","id":"GHSA-mhwj-73qx-jqxm","indexable":true,"kev":null,"kind":"advisory","links":{"ecosystem":"npm","product":null,"products":[],"type":"deserialization","year":"2026"},"n_packages":2,"n_references":null,"packages":[{"ecosystem":"npm","fixed":["1.0.1"],"introduced":["0"],"last_affected":[],"package":"@theecryptochad/merge-guard","purl":null,"source":"GHSA-mhwj-73qx-jqxm"},{"ecosystem":"npm","fixed":["1.0.1"],"introduced":["0"],"last_affected":[],"package":"@theecryptochad/merge-guard","purl":"pkg:npm/%40theecryptochad/merge-guard","source":"GHSA-mhwj-73qx-jqxm"}],"products":null,"published":"2026-05-11","related":[],"sources":[{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":null,"updated":null,"vendors":null},"summary":"Prototype pollution in deepMerge allows attackers to inject properties into Object.prototype, leading to privilege escalation or logic bypass.","url":"https://insights.sbomify.com/GHSA-mhwj-73qx-jqxm/"}