# CVE-2026-120203: ShowDoc 2.8.14 before 3.9.6 Code Injection via Mock Templates

Status: published. Published: 2026-10-31. Updated: 2026-11-06.

ShowDoc 2.8.14 before 3.9.6 contains a code injection vulnerability in its Mock feature that allows authenticated users to execute shell commands through mockjs templates. Attackers can store a template via MockController::add with escaped parentheses that mockjs evaluates with eval(), then trigger it through MockController::infoByKey to run commands, as root in the official Docker image.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/star7th/showdoc/commit/5a2087a3f408f5266f61e9e2fb98845ef4788288

## Affected products and versions

- ShowDoc / ShowDoc (showdoc/showdoc): ≥ 2.8.14; < 3.9.6 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 8.8 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H; source: CNA: VulnCheck

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 8.8 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.35% as of 2026-11-06; percentile 28.98%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-94

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/star7th/showdoc/commit/5a2087a3f408f5266f61e9e2fb98845ef4788288 (CNA: VulnCheck; patch)

- https://gist.github.com/LioTree/028af150fd991cf9924dd2c7d5912e54 (CNA: VulnCheck; technical-description)

- https://github.com/star7th/showdoc/blob/v3.9.5/mock/index.js#L42 (CNA: VulnCheck; technical-description)

- https://github.com/star7th/showdoc (CNA: VulnCheck; product)

- https://www.vulncheck.com/advisories/showdoc-2.8.14-before-3.9.6-code-injection-via-mock-templates (CNA: VulnCheck; third-party-advisory)

- https://gist.github.com/LioTree/028af150fd991cf9924dd2c7d5912e54 (disclosure@vulncheck.com)

- https://github.com/star7th/showdoc (disclosure@vulncheck.com)

- https://github.com/star7th/showdoc/blob/v3.9.5/mock/index.js#L42 (disclosure@vulncheck.com)

- https://github.com/star7th/showdoc/commit/5a2087a3f408f5266f61e9e2fb98845ef4788288 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/showdoc-2.8.14-before-3.9.6-code-injection-via-mock-templates (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-120203; retrieved 2026-11-06; source updated 2026-11-06

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-120203; retrieved 2026-11-03; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-120203; retrieved 2026-11-06; source updated Not reported

Revision: 7301d896c7098788eee760c148fb2085af98f82c4f74d1a79b5b865d420c54ef

Canonical: https://y2.dev/cve/CVE-2026-120203

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.