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Fencer Intel
critical 9.8

CVE-2026-27971 json

Qwik affected by unauthenticated RCE via server$ Deserialization

published 8mo ago modified 4mo ago also EUVD-2026-9345 , GHSA-p9x5-jp3h-96mm

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.5%
EPSS 5.5% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known, plus a Nuclei check

Summary

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.

Patch / fix

  • npm @builder.io/qwik 1.19.1
  • qwik qwik 1.19.1

Is CVE-2026-27971 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
8mo ago

Exploit prediction

5.48% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Nuclei template Qwik - Unauthenticated RCE via server$ Deserialization nuclei detection template

CVSS scores

assigned by version score vector
CNA 4.0 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
CNA 4.0 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
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
npm @builder.io/qwik
<1.19.1
1.19.1

Affected products

  • QwikDev qwik

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.