CVE-2025-68280: Apache SIS XXE Vulnerability Explained

CVE-2025-68280 Overview

CVE-2025-68280 is an XML External Entity (XXE) vulnerability in Apache Spatial Information System (SIS), a Java library for developing geospatial applications. The flaw stems from improper restriction of external entity references [CWE-611] during XML parsing. An attacker who supplies a crafted XML file can force Apache SIS to disclose the contents of local files on the server processing the input.

The issue affects Apache SIS versions 0.4 through 1.5 inclusive. Version 1.6 addresses the vulnerability. Multiple SIS parsing paths are impacted, including GeoTIFF metadata, ISO 19115 metadata, Geography Markup Language (GML) coordinate reference systems, and GPS Exchange Format (GPX) files.

Critical Impact
Attackers can read arbitrary local files from servers that parse untrusted geospatial data through Apache SIS.

Affected Products

Apache SIS 0.4 through 1.5 (inclusive)
Applications embedding Apache SIS for GeoTIFF processing with the DGIWG GEO_METADATA tag
Applications embedding Apache SIS for ISO 19115, GML, or GPX parsing

Discovery Timeline

2026-01-05 - CVE-2025-68280 published to NVD
2026-01-05 - Apache Software Foundation publishes advisory on the security mailing list
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-68280

Vulnerability Analysis

Apache SIS parses several XML-based geospatial formats using Java's XML processing APIs. The affected parsers do not disable external entity resolution by default. When Apache SIS ingests an attacker-controlled XML document, the parser resolves SYSTEM identifiers or external Document Type Definition (DTD) references embedded in the input, causing the parser to fetch local files and inline their contents into the parsed document.

Because Apache SIS often runs server-side inside geospatial data pipelines, the process typically has read access to configuration files, credentials, and other sensitive artifacts on the host filesystem. An attacker who can submit a GeoTIFF, ISO 19115 metadata, GML, or GPX file to such a service can retrieve those files through the returned parsed output or through side channels exposed by the application.

User interaction is required in the sense that a target must parse the malicious input, but that action is routine in file-upload workflows, batch ingest jobs, and metadata catalog services.

Root Cause

The root cause is the absence of secure XML processing defaults in the parsing paths inside Apache SIS. The library invokes Java XML parsers without setting javax.xml.accessExternalDTD and related restrictions to an empty value, so external DTDs and system entities are resolved. This class of flaw is tracked as CWE-611: Improper Restriction of XML External Entity Reference.

Attack Vector

The attack vector is network-adjacent through any interface that accepts geospatial files consumed by Apache SIS. The attacker crafts an XML payload containing an external entity declaration such as <!ENTITY xxe SYSTEM "file:///etc/passwd"> and references that entity in a field that Apache SIS parses. Delivery mechanisms include:

Uploaded GeoTIFF files carrying a GEO_METADATA DGIWG tag with malicious embedded XML.
ISO 19115 metadata records submitted to a catalog service.
GML documents describing coordinate reference systems.
GPX track files ingested by a route or telemetry service.

No verified public proof-of-concept exploit is available. The vulnerability mechanism is described in the Apache advisory. See the Apache Security Thread for technical details.

Detection Methods for CVE-2025-68280

Indicators of Compromise

XML payloads containing <!DOCTYPE> declarations with external SYSTEM identifiers submitted to GeoTIFF, ISO 19115, GML, or GPX endpoints.
Outbound DNS or HTTP requests from Java processes running Apache SIS to attacker-controlled hosts, indicating out-of-band XXE exfiltration.
Unexpected file read syscalls from the SIS Java process targeting /etc/, application configuration directories, or credential stores.

Detection Strategies

Inspect ingested XML and XML-in-GeoTIFF payloads for ENTITY declarations with SYSTEM or PUBLIC identifiers before they reach Apache SIS.
Log the Apache SIS version in use and alert when versions 0.4 through 1.5 are loaded in production JVMs.
Correlate geospatial ingest events with outbound network connections from the parsing service to detect data exfiltration attempts.

Monitoring Recommendations

Monitor JVM java.io.FileInputStream access to sensitive paths during XML parsing operations.
Alert on egress traffic from geospatial services to non-allowlisted destinations.
Track error logs from Apache SIS parsers for entity resolution failures, which often accompany failed XXE attempts.

How to Mitigate CVE-2025-68280

Immediate Actions Required

Upgrade Apache SIS to version 1.6 in all environments that ingest external geospatial data.
Inventory all applications and services that embed Apache SIS as a dependency, including transitive dependencies.
Restrict which users and systems can submit XML, GeoTIFF, GML, and GPX files to services backed by Apache SIS until patched.

Patch Information

Apache Software Foundation released Apache SIS 1.6, which disables external entity resolution in the affected parsers. Refer to the Apache Security Thread and the Openwall OSS Security Update for advisory details.

Workarounds

Launch the Java runtime with the javax.xml.accessExternalDTD system property set to an empty string or a restrictive allowlist of protocols.
Run Apache SIS with the JVM flag -Djavax.xml.accessExternalDTD="" to block external DTD resolution.
Apply egress network filtering on hosts running Apache SIS to prevent out-of-band exfiltration if entity resolution cannot be disabled immediately.
Validate and sanitize inbound XML by stripping DOCTYPE declarations at an upstream proxy or preprocessing step.

bash

# Configuration example: disable external DTD access when launching Java
java -Djavax.xml.accessExternalDTD="" \
     -Djavax.xml.accessExternalSchema="" \
     -jar your-application.jar