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CVE-2026-25150: Qwik Prototype Pollution (CVSS 9.3)

CVE-2026-25150 is a critical severity prototype pollution in Qwik with a CVSS score of 9.3. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Last updated: Jun 17, 2026

Quick answer

Direct answer

CVE-2026-25150 is a critical severity prototype pollution in Qwik with a CVSS score of 9.3. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Risk scores

CVSS base score
9.3CRITICAL
EPSS probability
0.72%
Higher than 53 percent of all CVEs
CISA KEV
Not listed
CVSS metricWhat it means
Attack vector (AV:N)Network: reachable remotely
Attack complexity (AC:L)Low complexity
Privileges required (PR:N)No privileges required
User interaction (UI:N)No user interaction
Scope (S:C)Scope changed: impact spreads beyond the component
Confidentiality (C:N)No confidentiality impact
Integrity (I:H)High integrity impact
Availability (A:L)Low availability impact

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L

About Qwik

CVE-2026-25150 affects Qwik, a product from Qwik. Before acting, confirm where Qwik runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.

What the flaw is

In plain terms: Qwik is a performance focused javascript framework. Prior to version 1.19.0, a prototype pollution vulnerability exists in the formToObj() function within @builder.io/qwik-city middleware. The function processes form field names with dot notation (e.g., user.name) to create nested objects, but fails to sanitize dangerous property names like __proto__, constructor, and prototype. This allows unauthenticated attackers to pollute Object.prototype by sending crafted HTTP POST requests, potentially leading to privilege escalation, authentication bypass, or denial of service. This issue has been patched in version 1.19.0.

The weakness class is Prototype Pollution. Attacker input changes the base object of a JavaScript application.

Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Affected versions and timeline

FieldDetail
ProductQwik
Affected versionsQwik before 1.19.0
PublishedFeb 3, 2026
Last modifiedJun 17, 2026
Added to CISA KEVNot listed
Assigning CNAsecurity-advisories@github.com

How to detect it

  • Inventory every instance of Qwik and record the running version against the affected range above.
  • Check external attack surface scans for internet facing instances of the component.
  • Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
  • Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.

How to fix it

  • Apply the fixed version of Qwik named in the vendor advisory.
  • If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
  • Rescan after the change to prove the exposure is gone, then close the ticket.

CTEM action plan

CTEM stageWhat to do for this CVE
ScopeAdd every business service that depends on Qwik to the current CTEM cycle.
DiscoverFind all instances, including shadow and cloud deployments, and record versions and exposure.
PrioritizeRank using EPSS and CVSS together with asset exposure and business impact.
ValidateConfirm the flaw is reachable and exploitable in your environment and that compensating controls work.
MobilizeAssign the fix to the asset owner with a due date matched to the priority, then verify closure.

CWE References

Technical References

Frequently asked questions

CVE-2026-25150 is a critical severity prototype pollution in Qwik with a CVSS score of 9.3. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

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Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. In versions from 2.0.12 to before 2.0.39, a prototype pollution vulnerability exists in locutus. Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input contained a forbidden key, it is still possible to pollute Object.prototype via a crafted input using String.prototype. This issue has been patched in version 2.0.39.

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Swiper is a free and mobile touch slider with hardware accelerated transitions and native behavior. Versions 6.5.1 through 12.1.1 have a Prototype pollution vulnerability. The vulnerability resides in line 94 of shared/utils.mjs, where the indexOf() function is used to check whether user provided input contain forbidden strings. Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input contained a forbidden key, it is still possible to pollute Object.prototype via a crafted input using Array.prototype. The exploit works across Windows and Linux and on Node and Bun runtimes. Any application that processes attacker-controlled input using this package may be affected by the following: Authentication Bypass, Denial of Service and RCE. This issue is fixed in version 12.1.2.

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