CVE-2026-22186
XXE in Openmicroscopy Bio-Formats ≤ 8.3.0
Raw vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/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:XSummary
CVE-2026-22186 is a medium-severity Improper Restriction of XML External Entity Reference (CWE-611) vulnerability in Openmicroscopy Bio-Formats. Its CVSS base score is 4.6 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 4th 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 CM-6 (Configuration Settings) and SA-11 (Developer Testing and Evaluation) — 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.
Bio-Formats versions up to and including 8.3.0 contain CVE-2026-22186, an XML External Entity (XXE) vulnerability classified under CWE-611 in the Leica Microsystems metadata parsing component, such as XLEF files. The vulnerability arises from an insecurely configured DocumentBuilderFactory used to process Leica XML-based metadata files, enabling external entity expansion and external DTD loading.
Exploitation requires local access (AV:L) with low complexity (AC:L), no privileges (PR:N), and user interaction (UI:R), as indicated by the CVSS v3.1 base score of 7.1 (C:H/I:N/A:H/S:U). A local attacker can craft a malicious metadata file that, when opened in Bio-Formats, triggers server-side request forgery (SSRF) through outbound network requests, discloses readable local system resources, or causes a denial of service during XML parsing.
Advisories providing mitigation guidance and patch information are available from sources including the Open Microscopy Environment Bio-Formats documentation at https://docs.openmicroscopy.org/bio-formats/, the Bio-Formats GitHub security advisory at https://github.com/ome/bioformats/security/advisories/GHSA-x9vc-qh97-8gjp, the Full Disclosure mailing list at https://seclists.org/fulldisclosure/2026/Jan/6, and the VulnCheck advisory at https://www.vulncheck.com/advisories/bio-formats-xxe-in-leica-xlef-metadata-parser.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-1170
Vulnerability Data
Bio-Formats versions up to and including 8.3.0 contain an XML External Entity (XXE) vulnerability in the Leica Microsystems metadata parsing component (e.g., XLEF). The parser uses an insecurely configured DocumentBuilderFactory when processing Leica XML-based metadata files, allowing external entity expansion…
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and external DTD loading. A crafted metadata file can trigger outbound network requests (SSRF), access local system resources where readable, or cause a denial of service during XML parsing.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.5.1V15.3.2
Mitigating Controls (NIST 800-53 r5) AI
Secure configuration settings can disable external entity processing in XML parsers.
Developer testing can discover XXE flaws through targeted XML parsing tests.
Input validation can reject or sanitize XML containing external entity references.
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.
Hardened XML parser configurations directly disable external entity resolution.
Secure SDLC practices include input validation and safe XML parser configuration that prevent XXE.
Vulnerability scanning can discover XXE flaws but does not prevent their introduction in code.
Patching eliminates XXE-vulnerable parser versions but is only one aspect of software maintenance.
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.
Security testing in development catches XXE via static analysis and dynamic XML fuzzing.
Vulnerability management identifies and patches XML libraries with unsafe default entity settings.
Secure development life cycle mandates input validation and entity handling that directly prevents XXE.
Application security requirements explicitly call for disabling external entity processing in XML parsers.
Secure architecture principles include safe parser configuration that mitigates external entity risks.
Secure coding standards require disabling DTDs and external entities in XML processing.