Security Digest · Vulnerability record
CVE-2026-27971: Qwik vulnerable to Unauthenticated RCE via server$ Deserialization
Qwik is a performance focused javascript framework.
CVSS 9.2 Critical EPSS 2.9% · p87
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 2.9%, percentile 87: FIRST’s model estimates a 2.9% chance of exploitation activity in the next 30 days, higher than 87% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
@builder.io/qwik(npm) <= 1.19.0, fixed in 1.19.1. Check your lockfile, including transitive dependencies.
What it is
Qwik is a performance focused javascript framework. qwik
From the GitHub advisory
Summary qwik
Impact - Remote Code Execution
Weakness type: CWE-502.
Product: @builder.io/qwik (npm) · Assigned by: GitHub_M · Published: 2026-03-03
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | @builder.io/qwik | <= 1.19.0 | 1.19.1 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| QwikDev | qwik | < 1.19.1 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 4.0 | 9.2 Critical | 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 |
| GitHub | 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 |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: present (depends on deployment conditions)
- Privileges required: none (no login)
- User interaction: none
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 2.95% probability of exploitation activity in the next 30 days; percentile 87.
Timeline
- — GitHub-reviewed advisory GHSA-p9x5-jp3h-96mm published (critical)
- — CVE record published by GitHub_M
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-p9x5-jp3h-96mm github.com
- CVE.org record CVE-2026-27971 cve.org
- NVD entry CVE-2026-27971 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com