PSA-2026-00081: Proxmox Virtual Environment: User impersonation via inconsistent ticket encoding
This Proxmox advisory covers a security issue in Proxmox Virtual Environment.
Key facts
- Fixed in
- libpve-common-perl 9.2.5
- Advisory id
- PSA-2026-00081
- Source published
- Listed by VulniPulse
Compiled by VulniPulse from the linked sources. How records are collected and checked.
Affected products & platforms
Description
Incosistent handling of encoding/decoding usernames in authentication tickets allows an attacker to impersonate other users in the same realm. This attack requires sufficient privileges to create users in a realm, or access to an OIDC/LDAP/AD source of user identifiers that does not restricted usernames to forbid certain characters.
This issue was discovered internally, and later also reported by Apo - CSB Raccoon. Packages: libpve-common-perl.
Affected product named by the advisory: Proxmox Virtual Environment.
Text from the source record.
Fix and mitigation
Upgrade to a fixed release named by Proxmox:
- libpve-common-perl 9.2.5
Vendor guidance
- Update to the fixed package versions: libpve-common-perl >= 9.2.5.
End-of-life dates for Proxmox VE
More Proxmox advisories
PSA-2026-00095Nov 10, 2026Proxmox Virtual Environment: Broken privilege checks when modifying container NICsPSA-2026-00094Nov 10, 2026Proxmox Virtual Environment: OCI extraction path escapePSA-2026-00093Nov 10, 2026Proxmox Virtual Environment: FRR config injection issuesPSA-2026-00092Nov 10, 2026Proxmox Virtual Environment: Missing and incomplete ACL checks in the SDN APIPSA-2026-00089Nov 10, 2026Proxmox: Several issues in libpve-http-server-perlPSA-2026-00088Nov 10, 2026Proxmox Virtual Environment: Shell command injection via volume name
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