CVE-2026-26338

CriticalPublic PoC

Published: 19 February 2026

Published

19 February 2026

Modified

02 March 2026

KEV Added

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Patch

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CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0011 29.5th percentile

Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-26338 is a critical-severity SSRF (CWE-918) vulnerability in Hyland Alfresco Transform Core. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 29.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

prevent

Directly remediates the SSRF vulnerability by applying Hyland's security update to the Alfresco Transformation Service document processing functionality.

SI-10 Information Input Validation good match

prevent

Validates and sanitizes unauthenticated inputs to the document processing endpoint to prevent SSRF payloads from inducing arbitrary server requests.

AC-4 Information Flow Enforcement good match

prevent

Enforces flow control policies restricting the service from making unauthorized outbound requests to internal or external resources exploited via SSRF.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

CVE-2026-26338 is an unauthenticated SSRF vulnerability in a public-facing document processing endpoint of the Hyland Alfresco Transformation Service, directly enabling exploitation of public-facing applications for initial access.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

Hyland Alfresco Transformation Service allows unauthenticated attackers to achieve server-side request forgery (SSRF) through the document processing functionality.

Deeper analysisAI

CVE-2026-26338 is a server-side request forgery (SSRF) vulnerability, classified under CWE-918, in the Hyland Alfresco Transformation Service. The flaw resides in the document processing functionality, enabling unauthenticated attackers to exploit it. Published on 2026-02-19, it carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity due to its network accessibility, low attack complexity, and potential for high impacts across confidentiality, integrity, and availability.

Unauthenticated remote attackers require no privileges or user interaction to exploit this vulnerability. By targeting the document processing endpoint, attackers can induce the service to make arbitrary requests to internal or external resources, facilitating SSRF attacks that may lead to unauthorized data access, service disruption, or further compromise depending on network configuration.

Hyland has issued a security update addressing CVE-2026-26338 alongside CVE-2026-26337 and CVE-2026-26339, available via their connect portal. Additional analysis appears in a Vulncheck advisory focused on the SSRF in the Alfresco Transformation Service. Security practitioners should consult these references for patch availability and mitigation recommendations.