Bug 2487740 (CVE-2026-46625) - CVE-2026-46625 js-cookie: JavaScript Cookie: Cookie attribute manipulation via prototype pollution
Summary: CVE-2026-46625 js-cookie: JavaScript Cookie: Cookie attribute manipulation vi...
Keywords:
Status: NEW
Alias: CVE-2026-46625
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2511391 2511392 2511394 2511395 2511401
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-10 22:01 UTC by OSIDB Bzimport
Modified: 2026-08-05 08:51 UTC (History)
89 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:48151 0 None None None 2026-07-29 19:54:49 UTC

Description OSIDB Bzimport 2026-06-10 22:01:40 UTC
JavaScript Cookie is a JavaScript API for handling cookies, client-side. Prior to version 3.0.7, js-cookie's internal assign() helper copies properties with for...in + plain assignment. When the source object is produced by JSON.parse, the JSON object's "__proto__" member is an own enumerable property, so the for…in enumerates it and the target[key] = source[key] write triggers the Object.prototype.__proto__ setter on the fresh target ({}). The result is a per-instance prototype hijack: Object.prototype itself is untouched, but the merged attributes object now inherits attacker-controlled keys. Because the consuming set() function then enumerates the merged object with another for...in, every key the attacker placed on the polluted prototype lands in the resulting Set-Cookie string as an attribute pair. The attacker can set domain=, secure=, samesite=, expires=, and path= on cookies whose attributes the developer thought were locked down. This issue has been patched in version 3.0.7.

Comment 1 errata-xmlrpc 2026-07-29 19:54:44 UTC
This issue has been addressed in the following products:

  Cryostat 4 on RHEL 9

Via RHSA-2026:48151 https://access.redhat.com/errata/RHSA-2026:48151


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