Microsoft PowerShell: XML external entity reference allows information disclosure
Summary
Microsoft PowerShell 7.6 and 7.7 contain an XML external entity (XXE) reference weakness (CWE-611). A remote, unauthenticated attacker can read information from the affected system over the network, but only if a user is tricked into interacting and the environment processes attacker-controlled XML. The CVE record describes information disclosure only, with no stated integrity or availability impact.
Affected
- PowerShell 7.6: 7.6.0 to before 7.6.10
- PowerShell 7.7: 1.0.0 to before 7.7.0 (range as stated by the CNA; to be verified on MSRC)
- Windows PowerShell 5.1: not listed in the CVE record; to be confirmed on MSRC
Fixed in
- PowerShell 7.6: 7.6.10 (per CVE record; not yet confirmed by the vendor advisory)
- PowerShell 7.7: 7.7.0 (per CVE record; not yet confirmed by the vendor advisory)
- Note: the 7.6.10 GitHub release notes list no XML or security fix; this conflict is open.
Workaround
Unknown.
- Limit which scripts and accounts process XML from untrusted sources until the vendor guidance is confirmed.
Exploitation
- Exploited in the wild: no evidence found.
- Not listed in CISA KEV as of the sources checked (to be confirmed on CISA's site).
- Public proof of concept: none found.
- CISA SSVC: exploitation none, not automatable, partial technical impact.
Our recommendation
- Check whether PowerShell 7.6 or 7.7 is installed, especially on servers, admin workstations and automation hosts that parse external XML.
- Check Windows PowerShell 5.1 hosts against the MSRC advisory.
- Once the MSRC fixed-build details are confirmed, update PowerShell 7.6 and 7.7 in the normal patch cycle.
- Monitor for public proof of concept and KEV listing.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE record (CNA) www.cve.org
- MSRC Security Update Guide msrc.microsoft.com
- PowerShell 7.6.10 release github.com
- Rapid7 Patch Tuesday, November 2026 www.rapid7.com
- Strix CVE mirror (secondary) www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 14:18.
Original description (NVD)
Improper restriction of xml external entity reference in Microsoft PowerShell allows an unauthorized attacker to disclose information over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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