CVE-2026-62682: Orval: RCE via servers[].url -> unescaped request-URL template literal (with getBaseUrlFromSpecification)

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 0.7%, percentile 51: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 51% of all scored CVEs (moderate). 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 orval (npm) < 8.21.0, fixed in 8.21.0. Check your lockfile, including transitive dependencies.

What it is

Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, an unescaped backtick in servers[0].url is emitted into request URL template literals generated when output.baseUrl.getBaseUrlFromSpecification is enabled without safe encoding. This permits attacker-controlled JavaScript to be evaluated when a generated request or URL-builder function is called, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/core/src/getters/route.ts function getFullRoute. This issue is fixed in version 8.21.0.

From the GitHub advisory

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

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

Weakness type: CWE-94, CWE-116, CWE-1336.

Product: orval (npm) · Assigned by: GitHub_M · Published: 2026-08-19

Affected and fixed versions

Severity scores

• 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 yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.65% probability of exploitation activity in the next 30 days; percentile 51.

Timeline

• 2026-08-19 — CVE record last updated
• 2026-08-19 — CVE record published by GitHub_M
• 2026-09-03 — GitHub-reviewed advisory GHSA-88f2-fpv8-89q2 published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-88f2-fpv8-89q2 github.com
2. CVE.org record CVE-2026-62682 cve.org
3. NVD entry CVE-2026-62682 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com

Critical npm advisories · Today’s Security Digest