Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-26339 is a critical-severity SSRF (CWE-918) vulnerability in Hyland Alfresco Transform Service. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 43th 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 map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-26339 is an argument injection vulnerability in the Hyland Alfresco Transformation Service, specifically within its document processing functionality. This flaw allows unauthenticated attackers to achieve remote code execution (RCE). The vulnerability has 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, lack of required privileges or user interaction, and potential for high confidentiality, integrity, and availability impacts. It is associated with CWE-918.
Unauthenticated remote attackers can exploit this vulnerability over the network without privileges or user interaction. By injecting malicious arguments into the document processing pipeline, attackers gain the ability to execute arbitrary code on the affected system, potentially leading to full server compromise.
Advisories from Hyland and VulnCheck detail mitigations, including security updates referenced at https://connect.hyland.com/t5/alfresco-blog/security-update-cve-2026-26337-cve-2026-26338-cve-2026-26339/ba-p/496551 and https://www.vulncheck.com/advisories/hyland-alfresco-transformation-service-argument-injection-rce. Additional context on the affected Alfresco Platform is available at https://www.hyland.com/en/solutions/products/alfresco-platform. Security practitioners should consult these for patch deployment and workaround guidance.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-7801
Vulnerability Data
Hyland Alfresco Transformation Service allows unauthenticated attackers to achieve remote code execution through the argument injection vulnerability, which exists in the document processing functionality.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
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.
Secure development practices directly include input validation and destination allow-listing that prevent SSRF.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
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.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.