Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-51080 is a critical-severity Improper Restriction of XML External Entity Reference (CWE-611) vulnerability in Proxmox (inferred from references). 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 22th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and CM-6 (Configuration Settings) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-45180
Vulnerability Data
libpvestorage-perl v9.1.1 and libpve-storage-perl v8.3.7 were discovered to contain an XML External Entity (XXE) vulnerability.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
XXE vulnerability (CWE-611) in storage library directly enables exploitation of the public-facing Proxmox VE application for initial access and local file disclosure.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces validation and sanitization of untrusted XML input to block external entity declarations that enable the XXE attack in the affected Perl storage libraries.
Requires secure configuration of XML parsers (e.g., disabling external entities and DTDs) so the vulnerable libpve-storage code cannot process malicious XXE payloads.
Mandates timely patching or updating of the flawed libpvestorage-perl and libpve-storage-perl components to eliminate the XXE code path.
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.