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GHSA-88f2-fpv8-89q2

CriticalCVSS 9.3 / 10
Published Sep 3, 2026·Last modified Sep 3, 2026
Affected Components(1)
npm logoorval
< 8.21.0
Description

Summary

When Orval is configured with output.baseUrl.getBaseUrlFromSpecification: true, it bakes the spec's servers[0].url into the generated request URL as a template literal without escaping the backtick. A server URL containing a backtick closes the template literal and injects a concatenation expression evaluated when the generated URL/request function is called, executing attacker-controlled code. Verified on Orval 8.19.0 (fetch client); survives default OpenAPI validation.

Details

return `http://api.x/` + (globalThis.X = require("fs").writeFileSync("/marker","pwned")) + `/v1/u`;

Prerequisite: the documented getBaseUrlFromSpecification: true option (takes the base URL from the OpenAPI servers block). This is the same output sink as the route-path case (request-URL template literal) reached via the server url field. Distinct from Orval's published CVEs (CVE-2026-22785 summary/MCP, CVE-2026-23947 / CVE-2026-25141 x-enumDescriptions, CVE-2026-24132 const/mock).

PoC

reproduce.sh (+ make_spec.py) attached: generates a fetch client with getBaseUrlFromSpecification: true, bundles it, calls the functions, and shows a marker written. Verified on 8.19.0.

Impact

With that option enabled, code execution in any environment that calls a client generated from an attacker-controlled or attacker-influenced OpenAPI description.

Suggested fix

Escape the server URL before emitting it into the URL template literal (escape backtick and ${), or build the base URL with an encoder that treats it as data; validate the URL. maintainer-report.txt make_spec.py reproduce.sh

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Risk Scores
Base Score
9.3

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
8.1

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.65%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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