CVE-2025-5276Public exploitNetwork attack vector

Sensitive data disclosure via unvalidated URL fetches

Published May 29, 2025 · Updated Aug 5, 2026

SSRF in mcp-markdownify-server before 1.0.0 allows remote attackers to read sensitive data through crafted prompts. Markdownify.get passes tool-supplied URLs to webpage, Bing, and YouTube conversion requests without validating the scheme or rejecting private destinations. An MCP host must access attacker-controlled prompt content and invoke the exposed conversion tools; successful requests disclose reachable responses.

CVSS severity7.4
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in mcp-markdownify-server before 1.0.0 allows remote attackers to read sensitive data through crafted prompts. Markdownify.get passes tool-supplied URLs to webpage, Bing, and YouTube conversion requests without validating the scheme or rejecting private destinations. An MCP host must access attacker-controlled prompt content and invoke the exposed conversion tools; successful requests disclose reachable responses.

The record

CVE
CVE-2025-5276
Published
May 29, 2025
Updated
Aug 5, 2026
Vendor
Zach Caceres
Product
mcp-markdownify-server
Classifications
CWE-918, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zach Caceres · mcp-markdownify-serverversion=0 <1.0.0

Published CVSS scores

7.4SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
6.9SnykCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1005Data from Local System

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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