Security Digest · Vulnerability record
CVE-2025-53620: Qwik's unhandled exception vulnerabilty can cause server crashes from malicious requests
@builder.io/qwik-city is the meta-framework for Qwik.
CVSS 9.2 Critical EPSS 0.4% · p28
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.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.4%, percentile 28: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 28% of all scored CVEs (low). 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-city(npm) < 1.13.0, fixed in 1.13.0. Check your lockfile, including transitive dependencies.
What it is
@builder.io/qwik-city is the meta-framework for Qwik. When a Qwik Server Action QRL is executed it dynamically load the file containing the symbol. When an invalid qfunc is sent, the server does not handle the thrown error. The error then causes Node JS to exit. This vulnerability is fixed in 1.13.0.
From the GitHub advisory
Summary
Possibility to craft a request that will crash the Qwik Server in the default configuration.
Details
When a Qwik Server Action QRL is executed it dynamically load the file containing the symbol. When an invalid qfunc is sent, the server does not handle the thrown error. The error then causes Node JS to exit.
PoC
Weakness type: CWE-248.
Product: @builder.io/qwik-city (npm) · Assigned by: GitHub_M · Published: 2025-07-09
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | @builder.io/qwik-city | < 1.13.0 | 1.13.0 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| QwikDev | qwik | < 1.13.0 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 4.0 | 9.2 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H |
| GitHub | 4.0 | 9.2 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: none
- 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 poc, automatable no, technical impact partial.
- FIRST EPSS (model of 2026-10-21): 0.36% probability of exploitation activity in the next 30 days; percentile 28.
Timeline
- — CVE record last updated
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-qr9h-j6xg-2j72 published (critical)
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-qr9h-j6xg-2j72 github.com
- CVE.org record CVE-2025-53620 cve.org
- NVD entry CVE-2025-53620 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
- github.com github.com