CVE-2026-48359: Adobe Experience Manager XXE Vulnerability

CVE-2026-48359 Overview

CVE-2026-48359 is an XML External Entity (XXE) vulnerability affecting Adobe Experience Manager (AEM). The flaw stems from improper restriction of XML external entity references [CWE-611] during XML parsing. A low-privileged, authenticated attacker can exploit this vulnerability over the network without user interaction.

Successful exploitation allows attackers to read sensitive files, achieve arbitrary code execution in the context of the current user, and pivot to elevated access. The scope is changed, meaning impact extends beyond the vulnerable component to other resources.

Critical Impact
Attackers with low privileges can read arbitrary files, execute code, and hijack sessions across the AEM environment without any user interaction.

Affected Products

Adobe Experience Manager (on-premise, all versions prior to the APSB26-74 fix)
Adobe Experience Manager Cloud Service
Adobe Experience Manager 6.5 LTS (including SP1 and SP2)

Discovery Timeline

2026-07-14 - CVE-2026-48359 published to the National Vulnerability Database
2026-07-17 - Last updated in NVD database

Technical Details for CVE-2026-48359

Vulnerability Analysis

CVE-2026-48359 is classified as an Improper Restriction of XML External Entity Reference [CWE-611] vulnerability in Adobe Experience Manager. AEM processes untrusted XML input without disabling external entity resolution in its underlying XML parser.

When an attacker submits crafted XML containing external entity declarations, the parser resolves references to attacker-controlled or local resources. This behavior enables file disclosure, server-side request forgery, and downstream code execution paths inside the AEM Java runtime.

The changed scope indicator (S:C) shows that the vulnerability impacts resources beyond the vulnerable AEM component. In practice, this means attackers can reach backend systems, connected repositories, or cloud metadata services reachable from AEM.

Root Cause

The root cause is an XML parser configuration that does not disable Document Type Definition (DTD) processing or external entity resolution. XML parsers such as DocumentBuilderFactory, SAXParserFactory, and XMLInputFactory are insecure by default in Java and must be explicitly hardened. AEM components accepting XML fail to apply these hardening flags.

Attack Vector

An attacker authenticates to AEM with any low-privileged account and submits crafted XML payloads to endpoints that parse XML content. Payloads reference external entities using SYSTEM identifiers pointing to local files such as /etc/passwd or file:/// URIs. Attackers can also chain the flaw with SSRF to reach internal services or cloud instance metadata endpoints, exfiltrating credentials that enable arbitrary code execution.

No verified public proof-of-concept is available at the time of publication. Refer to the Adobe Security Bulletin APSB26-74 for vendor-provided technical details.

Detection Methods for CVE-2026-48359

Indicators of Compromise

HTTP POST or PUT requests to AEM endpoints containing XML payloads with <!DOCTYPE, <!ENTITY, or SYSTEM declarations
Outbound DNS or HTTP requests from AEM servers to unexpected external hosts, indicating out-of-band XXE data exfiltration
Unexpected file reads of sensitive files (/etc/passwd, /etc/shadow, AEM configuration files) by the AEM Java process
Access attempts to cloud instance metadata endpoints (for example, 169.254.169.254) originating from AEM workloads

Detection Strategies

Inspect application logs for XML parsing errors referencing external entities or blocked DTD resolution attempts
Monitor authenticated sessions submitting XML content types (application/xml, text/xml) to non-standard AEM endpoints
Correlate authenticated user activity with anomalous file access or outbound network calls from the AEM JVM

Monitoring Recommendations

Enable verbose logging on AEM dispatcher and Sling servlets that accept XML input, and forward logs to a centralized SIEM
Alert on process-level file reads of sensitive OS files by the AEM service account
Baseline outbound traffic from AEM hosts and alert on new destinations, especially internal RFC1918 or link-local addresses

How to Mitigate CVE-2026-48359

Immediate Actions Required

Apply the updates listed in Adobe Security Bulletin APSB26-74 to all AEM on-premise, Cloud Service, and 6.5 LTS deployments
Audit AEM user accounts and revoke unnecessary low-privileged access that could be abused to reach XML-processing endpoints
Restrict network egress from AEM hosts to block out-of-band XXE exfiltration channels
Review AEM access logs for suspicious XML payloads submitted since deployment

Patch Information

Adobe released fixes in security bulletin APSB26-74 covering AEM Cloud Service, AEM 6.5 LTS, and on-premise builds. Administrators should apply the vendor-specified service pack or cloud release referenced in the Adobe Security Bulletin APSB26-74.

Workarounds

Place a web application firewall (WAF) in front of AEM to block XML payloads containing <!DOCTYPE or <!ENTITY declarations until patches are applied
Enforce network segmentation to prevent AEM from reaching cloud metadata services and internal management interfaces
Harden custom XML parsers in AEM extensions by disabling DTDs and external entity resolution at the parser level

bash

# Example: Java XML parser hardening to disable external entities
# Apply in custom AEM bundles that instantiate XML parsers
factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
factory.setFeature("http://xml.org/sax/features/external-general-entities", false);
factory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
factory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
factory.setXIncludeAware(false);
factory.setExpandEntityReferences(false);