Forge: Prototype Pollution in forge.http cookie handling via a malicious Set-Cookie
cve-program · CVE-2026-118777
PublishedForge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the forge.http client stored cookie names and paths from Set-Cookie response headers in ordinary JavaScript objects. A malicious server could use the cookie name __proto__ so that the attacker-controlled cookie path was written as a property on Object.prototype, or use inherited names such as constructor to modify Object. An empty cookie value could use the removal path to delete an inherited Object.prototype property. Applications using forge.http directly or through forge.xhr are affected; applications that do not use forge.http are unaffected. This issue is fixed in version 1.4.1.
Read the publisher's advisoryeuvd · EUVD-2026-113335
PublishedForge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the forge.http client stored cookie names and paths from Set-Cookie response headers in ordinary JavaScript objects. A malicious server could use the cookie name __proto__ so that the attacker-controlled cookie path was written as a property on Object.prototype, or use inherited names such as constructor to modify Object. An empty cookie value could use the removal path to delete an inherited Object.prototype property. Applications using forge.http directly or through forge.xhr are affected; applications that do not use forge.http are unaffected. This issue is fixed in version 1.4.1.
Read the publisher's advisorynvd · CVE-2026-118777
PublishedForge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the forge.http client stored cookie names and paths from Set-Cookie response headers in ordinary JavaScript objects. A malicious server could use the cookie name __proto__ so that the attacker-controlled cookie path was written as a property on Object.prototype, or use inherited names such as constructor to modify Object. An empty cookie value could use the removal path to delete an inherited Object.prototype property. Applications using forge.http directly or through forge.xhr are affected; applications that do not use forge.http are unaffected. This issue is fixed in version 1.4.1.
Read the publisher's advisoryosv · GHSA-6wvx-3r32-xmcg
Published### Summary The `forge.http` client stored cookies from `Set-Cookie` response headers in a plain object keyed by cookie name and path. A malicious server could use the cookie name `__proto__` to add properties to `Object.prototype`, use inherited names such as `constructor` to add properties to `Object`, and send an empty cookie value to delete `Object.prototype` properties. Fixed in node-forge 1.4.1. ### Details `client.setCookie()` in `lib/http.js` stored a cookie with `client.cookies[cookie.name][cookie.path] = cookie`, creating `client.cookies[cookie.name]` only when `!(cookie.name in client.cookies)`. Both values come from the server's `Set-Cookie` header via `response.getCookies()`. Because `in` also sees inherited properties: - a cookie named `__proto__` skipped the initialization, `client.cookies['__proto__']` returned `Object.prototype`, and the cookie path was written as a new `Object.prototype` property, visible on every object; - a cookie named `constructor` wrote onto the global `Object` function the same way; - a cookie with an empty value calls `client.removeCookie(name, path)`, which used the same `in` checks and then `delete client.cookies[name][path]`, so `Set-Cookie: __proto__=; path=toString` deleted `Object.prototype.toString`. This path skipped the cookie's secure-flag and domain checks, so it also worked for `http://` clients. `forge.http` is not loaded by `require('node-forge')`. It is included in the `forge.all` browser bundle and is used with a socket pool, for example by `forge.xhr`. The fix uses own-property checks for the cookie store and ignores cookies named `__proto__` or with the path `__proto__`. #### Patches Fixed in node-forge 1.4.1. Cookies from a server can no longer add or remove properties of `Object.prototype` or `Object`. #### Workarounds Don't use `forge.http` or `forge.xhr` with servers that aren't trusted, or filter `Set-Cookie` headers named `__proto__`, `constructor` or other `Object.prototype` property names before they reach the client. #### Credits Reported by @arunmozhivarman-dtx and @Dremig. ### Proof of concept A server response for a `forge.http` client (`http.createClient({url: 'https://...', socketPool: ...})`) containing: Set-Cookie: __proto__=evil; path=polluted On 1.4.0, after the client processes the response, `({}).polluted` is the cookie object. With `Set-Cookie: __proto__=; path=toLocaleString`, `Object.prototype.toLocaleString` is deleted (for `http://` and `https://` clients). On 1.4.1 these cookies are ignored and `Object.prototype` is unchanged. Regression tests are in tests/security/ghsa-6wvx-3r32-xmcg.js. ### Impact Applications that use the `forge.http` client (directly, or through `forge.xhr` in the `forge.all` browser bundle) against a server that can be malicious are affected. The server can add properties to `Object.prototype` and `Object` for the whole JavaScript realm, which can change application logic that reads properties from plain objects, and can delete built-in `Object.prototype` methods, breaking the page or process. Applications that don't use `forge.http` are not affected.
Read the publisher's advisoryAffected versions, risk and source history
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cve-program · CVE-2026-118777
PublishedForge: Prototype Pollution in forge.http cookie handling via a malicious Set-Cookie
Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the forge.http client stored cookie names and paths from Set-Cookie response headers in ordinary JavaScript objects. A malicious server could use the cookie name __proto__ so that the attacker-controlled cookie path was written as a property on Object.prototype, or use inherited names such as constructor to modify Object. An empty cookie value could use the removal path to delete an inherited Object.prototype property. Applications using forge.http directly or through forge.xhr are affected; applications that do not use forge.http are unaffected. This issue is fixed in version 1.4.1.
- Source published
- 29 Oct 2026 18:42:06 UTC
- Source modified
- 30 Oct 2026 17:12:06 UTC
- Saved here
- 30 Oct 2026 18:45:26 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
euvd · EUVD-2026-113335
PublishedForge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the forge.http client stored cookie names and paths from Set-Cookie response headers in ordinary JavaScript objects. A mali…
Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the forge.http client stored cookie names and paths from Set-Cookie response headers in ordinary JavaScript objects. A malicious server could use the cookie name __proto__ so that the attacker-controlled cookie path was written as a property on Object.prototype, or use inherited names such as constructor to modify Object. An empty cookie value could use the removal path to delete an inherited Object.prototype property. Applications using forge.http directly or through forge.xhr are affected; applications that do not use forge.http are unaffected. This issue is fixed in version 1.4.1.
Additional publisher context
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Oct 29, 2026, 6:42:06 PM
dateUpdated: Oct 30, 2026, 5:12:06 PM
1 related source bulletins · separate from aliases
msrc_CVE-2026-118777: Forge: Prototype Pollution in forge.http cookie handling via a malicious Set-Cookie
CVE-2026-118777
- Source published
- Oct 29, 2026, 6:42:06 PM (timezone not stated)
- Source modified
- Oct 30, 2026, 5:12:06 PM (timezone not stated)
- Saved here
- 14 Nov 2026 06:08:00 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
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EUVD CVSS 3.1 · 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
nvd · CVE-2026-118777
PublishedForge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the forge.http client stored cookie names and paths from Set-Cookie response headers in ordinary JavaScript objects. A mali…
Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the forge.http client stored cookie names and paths from Set-Cookie response headers in ordinary JavaScript objects. A malicious server could use the cookie name __proto__ so that the attacker-controlled cookie path was written as a property on Object.prototype, or use inherited names such as constructor to modify Object. An empty cookie value could use the removal path to delete an inherited Object.prototype property. Applications using forge.http directly or through forge.xhr are affected; applications that do not use forge.http are unaffected. This issue is fixed in version 1.4.1.
Additional publisher context
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-1321
Original publisher date fields
published: 2026-10-29T19:17:20.283
lastModified: 2026-11-04T16:49:51.240
1 source CPE criteria · context only
- cpe:2.3:a:digitalbazaar:forge:*:*:*:*:*:*:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 29 Oct 2026 19:17:20 UTC
- Source modified
- 4 Nov 2026 16:49:51 UTC
- Saved here
- 6 Nov 2026 01:43:49 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · [email protected] · Secondary · 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
CVSS 3.1 · [email protected] · Primary · 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
osv · GHSA-6wvx-3r32-xmcg
PublishedForge: Prototype Pollution in forge.http cookie handling via a malicious Set-Cookie
### Summary The `forge.http` client stored cookies from `Set-Cookie` response headers in a plain object keyed by cookie name and path. A malicious server could use the cookie name `__proto__` to add properties to `Object.prototype`, use inherited names such as `constructor` to add properties to `Object`, and send an empty cookie value to delete `Object.prototype` properties. Fixed in node-forge 1.4.1. ### Details `client.setCookie()` in `lib/http.js` stored a cookie with `client.cookies[cookie.name][cookie.path] = cookie`, creating `client.cookies[cookie.name]` only when `!(cookie.name in client.cookies)`. Both values come from the server's `Set-Cookie` header via `response.getCookies()`. Because `in` also sees inherited properties: - a cookie named `__proto__` skipped the initialization, `client.cookies['__proto__']` returned `Object.prototype`, and the cookie path was written as a new `Object.prototype` property, visible on every object; - a cookie named `constructor` wrote onto the global `Object` function the same way; - a cookie with an empty value calls `client.removeCookie(name, path)`, which used the same `in` checks and then `delete client.cookies[name][path]`, so `Set-Cookie: __proto__=; path=toString` deleted `Object.prototype.toString`. This path skipped the cookie's secure-flag and domain checks, so it also worked for `http://` clients. `forge.http` is not loaded by `require('node-forge')`. It is included in the `forge.all` browser bundle and is used with a socket pool, for example by `forge.xhr`. The fix uses own-property checks for the cookie store and ignores cookies named `__proto__` or with the path `__proto__`. #### Patches Fixed in node-forge 1.4.1. Cookies from a server can no longer add or remove properties of `Object.prototype` or `Object`. #### Workarounds Don't use `forge.http` or `forge.xhr` with servers that aren't trusted, or filter `Set-Cookie` headers named `__proto__`, `constructor` or other `Object.prototype` property names before they reach the client. #### Credits Reported by @arunmozhivarman-dtx and @Dremig. ### Proof of concept A server response for a `forge.http` client (`http.createClient({url: 'https://...', socketPool: ...})`) containing: Set-Cookie: __proto__=evil; path=polluted On 1.4.0, after the client processes the response, `({}).polluted` is the cookie object. With `Set-Cookie: __proto__=; path=toLocaleString`, `Object.prototype.toLocaleString` is deleted (for `http://` and `https://` clients). On 1.4.1 these cookies are ignored and `Object.prototype` is unchanged. Regression tests are in tests/security/ghsa-6wvx-3r32-xmcg.js. ### Impact Applications that use the `forge.http` client (directly, or through `forge.xhr` in the `forge.all` browser bundle) against a server that can be malicious are affected. The server can add properties to `Object.prototype` and `Object` for the whole JavaScript realm, which can change application logic that reads properties from plain objects, and can delete built-in `Object.prototype` methods, breaking the page or process. Applications that don't use `forge.http` are not affected.
- Source published
- 30 Oct 2026 23:02:35 UTC
- Source modified
- 30 Oct 2026 23:15:05 UTC
- Saved here
- 30 Oct 2026 23:45:44 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
Publisher rating · MODERATE