CVE-2026-27971
CriticalExploitedQwik vulnerable to Unauthenticated RCE via server$ Deserialization
Published Mar 2, 2026 · Updated Aug 12, 2026 · Also known as GHSA-p9x5-jp3h-96mm
Key Facts
Patch immediately- CVE-2026-27971 is a critical-severity vulnerability (CVSS 9.2 v4) affecting Qwik, @builder.io/qwik (npm).
- It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Apr 1, 2026. No public exploit code is known.
- EPSS estimates a 2.9% probability of exploitation in the next 30 days.
- Fixed versions are available, including @builder.io/qwik 1.19.1, Qwik 1.19.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v4
9.2
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS (30-day exploit likelihood)
2.9%
Higher than 86.6% of all scored CVEs
Exploited in the wild
Yes
2 catalog listings
Public exploit code
None known
Get the full CVE-2026-27971 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Qwik is a performance focused javascript framework. qwik <=1.19.0 is vulnerable to RCE due to an unsafe deserialization vulnerability in the server$ RPC mechanism that allows any unauthenticated user to execute arbitrary code on the server with a single HTTP request. Affects any deployment where require() is available at runtime. This vulnerability is fixed in 1.19.1.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Apr 1, 2026 | n/a | Not reported |
| CIRCL KEV | Aug 22, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| QwikQwik | >= < 1.19.1 | 1.19.1 |
| @builder.io/qwiknpm | See advisory | 1.19.1 |
Patched Releases
@builder.io/qwik
1.19.1
Qwik
1.19.1
Timeline
Publicly disclosed
Mar 2, 2026
Added to Industry KEV feed
Apr 1, 2026
Last updated
Aug 12, 2026
Added to CIRCL KEV
Aug 22, 2026
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27971.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-27971
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
Qwik is a performance focused javascript framework.
Affected: Qwik versions >= < 1.19.1; @builder.io/qwik (npm). The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Apr 1, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including @builder.io/qwik 1.19.1, Qwik 1.19.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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