XSS in Middleapi Orpc
CVE-2026-33331
oRPC is an tool that helps build APIs that are end-to-end type-safe and adhere to OpenAPI standards. Prior to version 1.13.9, a stored cross-site scripting (XSS) vulnerability exists in the OpenAPI documentation generation of orpc. If an attacker can control any field within the OpenAPI specification (such as info.description), they can break out of the JSON context and execute arbitrary JavaScript when a user views the generated API documentation. This issue has been patched in version 1.13.9.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (25.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 25.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.001
Affected products
- Middleapi Orpc — versions < 1.13.9
- Orpc
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/middleapi/orpc/security/advisories/GHSA-7f6v-3gx7-27q8 (Exploit, Mitigation, Vendor Advisory)
- github.com/middleapi/orpc/commit/4f0efa8a1d3fa8e8317a4b03cc3945a5dfd68add (Patch)
- github.com/middleapi/orpc/releases/tag/v1.13.9 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-33331?
- CVE-2026-33331 is a high-severity vulnerability in Middleapi Orpc, classified under Cross-site Scripting. CVSS score: 8.2/10. Published 2026-03-24.
- How severe is CVE-2026-33331?
- High severity. CVSS v3 base score is 8.2 out of 10.
- Is CVE-2026-33331 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.