SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-71867

This permits attacker-controlled JavaScript to be evaluated when the generated mock factory is called by tests or an MSW handler, resulting in code execution in the developer, CI, test, or application environment.

CRITICAL 9.3EPSS 0.65%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.65%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Orval generates type-safe JavaScript clients in TypeScript from OpenAPI v3 and Swagger v2 specifications. Prior to 8.21.0, a single quote in a schema property name is emitted into single-quoted object keys in generated MSW mock factories without safe encoding. This permits attacker-controlled JavaScript to be evaluated when the generated mock factory is called by tests or an MSW handler, resulting in code execution in the developer, CI, test, or application environment. The affected code is packages/core/src/getters/keys.ts function getKey and MSW mock generation. This issue is fixed in version 8.21.0.

CVSS 4.0
9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/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/M
EPSS
0.65% probability · 51th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-89, CWE-95
Source
security-advisories@github.com
EPSS trend
0%3%5%26 October 2026: 0.65%26 October 202626 October 2026

EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.