Cyber Resilience

CVE-2026-5323

SSRF

Published
02 April 2026
Modified
27 April 2026
CVSS Score v4 4.8
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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
EPSS Score 0.0013 3th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-5323 is a medium-severity SSRF (CWE-918) vulnerability. Its CVSS base score is 4.8 (Medium).

Operationally, ranked at the 3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability was found in priyankark a11y-mcp up to 1.0.5. This vulnerability affects the function A11yServer of the file src/index.js. The manipulation results in server-side request forgery. The attack must be initiated from a local position. The exploit has been…

more

made public and could be used. This product operates on a rolling release basis, ensuring continuous delivery. Consequently, there are no version details for either affected or updated releases. Upgrading to version 1.0.6 is able to resolve this issue. The patch is identified as e3e11c9e8482bd06b82fd9fced67be4856f0dffc. It is recommended to upgrade the affected component. The vendor acknowledged the issue but provides additional context for the CVSS rating: "a11y-mcp is a local stdio MCP server - it has no HTTP endpoint and is not network-accessible. The caller is always the local user or an LLM acting on their behalf with user approval."

CWE(s)

AI Security AnalysisAI

AI Category
AI Agent Protocols and Integrations
Risk Domain
Protocol-Specific Risks
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: llm, mcp

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

Insufficient information to map techniques.
Confidence: LOW · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-56663Shared CWE-918
CVE-2025-65512Shared CWE-918
CVE-2026-42260Shared CWE-918
CVE-2026-44430Shared CWE-918
CVE-2026-7147Shared CWE-918
CVE-2026-10274Shared CWE-918
CVE-2025-5276Shared CWE-918
CVE-2026-15746Shared CWE-918
CVE-2026-32111Shared CWE-918
CVE-2026-40150Shared CWE-918

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • AC-4 Information Flow Enforcement
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Mitigating Controls (NIST 800-53 r5) AI

prevent

Validates untrusted inputs to the A11yServer function to block crafted URLs that trigger SSRF.

prevent

Enforces information flow rules so the local stdio server cannot initiate arbitrary outbound requests.

prevent

Restricts the privileges of the MCP server process, limiting the destinations or methods usable in an SSRF attempt.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly include input validation and destination allow-listing that prevent SSRF.

DE.CM-09 partial match
prevents

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
prevents

Network segmentation and egress controls can limit the damage from successful SSRF requests.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.

References