# CVE-2025-0520: ShowDoc < 2.8.7 Unauthenticated File Upload Remote Code Execution

Status: published. Published: 2025-04-29. Updated: 2026-11-08.

An unrestricted file upload vulnerability in ShowDoc caused by improper validation of file extension allows execution of arbitrary PHP, leading to remote code execution.This issue affects ShowDoc: before 2.8.7.

## 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/pull/1059

## Affected products and versions

- ShowDoc / ShowDoc (showdoc/showdoc): ≥ 0; < 2.8.7 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 9.4 (critical); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 2.44% as of 2026-11-08; percentile 84.45%

- SSVC: exploitation poc; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-434

## Exploit evidence

- exploit: https://github.com/vulhub/vulhub/tree/master/showdoc/CNVD-2020-26585 (CNA: VulnCheck)

## References

- https://github.com/vulhub/vulhub/tree/master/showdoc/CNVD-2020-26585 (CNA: VulnCheck; exploit)

- https://github.com/star7th/showdoc/pull/1059 (CNA: VulnCheck; issue-tracking, patch)

- https://www.cnvd.org.cn/flaw/show/CNVD-2020-26585 (CNA: VulnCheck; third-party-advisory)

- https://www.vulncheck.com/advisories/showdoc-unauthenticated-file-upload-rce (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2025-0520; retrieved 2026-11-08; source updated 2026-11-08

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2025-0520; retrieved 2026-11-08; source updated Not reported

Revision: 4593e791958199b5257d9c1e159c2fbb7b78f9074840ea75944d09a4d1fdc87c

Canonical: https://y2.dev/cve/CVE-2025-0520

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