https://db.gcve.eu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Mon, 28 Sep 2026 17:24:06 +0000 https://db.gcve.eu/vuln/fkie_cve-2026-61534 <p>Yayson is a library for serializing and reading JSON API data in JavaScript. Prior to 4.3.0, Store and LegacyStore use attacker-controlled JSON:API type, id, and relationship names as keys in plain-object lookup tables in src/yayson/store.ts and src/yayson/legacy-store.ts. A document whose type is __proto__ causes model-cache writes to modify Object.prototype, with the attacker controlling the polluted property name through id and its value through attributes. The malicious type can also be supplied by an included resource, and LegacyStore is reachable when a configured types mapping resolves to __proto__. Unsafe relationship names including __proto__, constructor, and prototype provide additional document-derived member paths. The resulting process-wide prototype pollution can cause denial of service and logic corruption; authorization bypass or code execution depends on suitable gadgets in the consuming application. This issue is fixed in version 4.3.0.</p> <p>Yayson is a library for serializing and reading JSON API data in JavaScript. Prior to 4.3.0, Store and LegacyStore use attacker-controlled JSON:API type, id, and relationship names as keys in plain-object lookup tables in src/yayson/store.ts and src/yayson/legacy-store.ts. A document whose type is __proto__ causes model-cache writes to modify Object.prototype, with the attacker controlling the polluted property name through id and its value through attributes. The malicious type can also be supplied by an included resource, and LegacyStore is reachable when a configured types mapping resolves to __proto__. Unsafe relationship names including __proto__, constructor, and prototype provide additional document-derived member paths. The resulting process-wide prototype pollution can cause denial of service and logic corruption; authorization bypass or code execution depends on suitable gadgets in the consuming application. This issue is fixed in version 4.3.0.</p> https://db.gcve.eu/vuln/fkie_cve-2026-61534 https://db.gcve.eu/vuln/ghsa-325j-mg25-8q58 <p><strong>Affected:</strong> npm: yayson</p> <p># Summary `Store`/`LegacyStore` key internal lookup tables by the `type`, `id`, and relationship names from a JSON:API document. Because these were plain objects, a document with `type: &#34;__proto__&#34;` writes onto `Object.prototype`, polluting every object in the process.</p> <p># Severity Suggested CVSS v3.1 `AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H` (8.1). The guaranteed impact is process-wide DoS / logic corruption; escalation to authorization bypass or RCE is dependent on gadgets in the consuming application.</p> <p># Affected / Patched - Affected: `&lt;= 4.2.0` (verified in `3.0.0` and `4.2.0`; all 3.x and 4.x). - Patched: `4.3.0`.</p> <p># Details `type` is a string *value*, untouched by `JSON.parse`, and is used directly as an object key: ```js if (!models[type]) models[type] = {} // models[&#34;__proto__&#34;] is Object.prototype → skipped if (!models[type][id]) models[type][id] = model // → Object.prototype[id] = model ``` The attacker controls the polluted key (`id`) and value (the model, populated from `attributes`). Pollution persists for the process lifetime. The malicious type can also arrive via an `included` resource referenced by a relationship, bypassing any `data.type` allow-list. `LegacyStore` is additionally reachable when a configured `types` mapping resolves to `&#34;__proto__&#34;`.</p> <p># Proof of concept ```js const { Store } = require(&#39;yayson&#39;)() new Store().sync({ data: { type: &#39;__proto__&#39;, id: &#39;polluted&#39;, attributes: { x: 1 } } }) console.log(({}).polluted) // { x: 1, id: &#39;polluted&#39; }…</p> <p><strong>Affected:</strong> npm: yayson</p> <p># Summary `Store`/`LegacyStore` key internal lookup tables by the `type`, `id`, and relationship names from a JSON:API document. Because these were plain objects, a document with `type: &#34;__proto__&#34;` writes onto `Object.prototype`, polluting every object in the process.</p> <p># Severity Suggested CVSS v3.1 `AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H` (8.1). The guaranteed impact is process-wide DoS / logic corruption; escalation to authorization bypass or RCE is dependent on gadgets in the consuming application.</p> <p># Affected / Patched - Affected: `&lt;= 4.2.0` (verified in `3.0.0` and `4.2.0`; all 3.x and 4.x). - Patched: `4.3.0`.</p> <p># Details `type` is a string *value*, untouched by `JSON.parse`, and is used directly as an object key: ```js if (!models[type]) models[type] = {} // models[&#34;__proto__&#34;] is Object.prototype → skipped if (!models[type][id]) models[type][id] = model // → Object.prototype[id] = model ``` The attacker controls the polluted key (`id`) and value (the model, populated from `attributes`). Pollution persists for the process lifetime. The malicious type can also arrive via an `included` resource referenced by a relationship, bypassing any `data.type` allow-list. `LegacyStore` is additionally reachable when a configured `types` mapping resolves to `&#34;__proto__&#34;`.</p> <p># Proof of concept ```js const { Store } = require(&#39;yayson&#39;)() new Store().sync({ data: { type: &#39;__proto__&#39;, id: &#39;polluted&#39;, attributes: { x: 1 } } }) console.log(({}).polluted) // { x: 1, id: &#39;polluted&#39; }…</p> https://db.gcve.eu/vuln/ghsa-325j-mg25-8q58