CVE-2026-85769

A flaw was found in libtpms, a library that provides software TPM 2.0 emulation. When restoring TPM 2.0 state (for example during a virtual machine's power-on or state/migration restore), a malformed state blob can supply an oversized skip-block length that is not validated against the remaining size of the input buffer. This can drive an internal size counter negative, which bypasses a subsequent bounds check due to an unsafe signed-to-unsigned conversion, causing the parser to read memory outside the bounds of the heap buffer holding the state data. Successful exploitation can crash the process hosting libtpms (such as swtpm), resulting in a denial of service of the emulated TPM device and the virtual machine that depends on it. No data corruption or information disclosure was confirmed.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector ADJACENT_NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/security/cve/CVE-2026-85769
https://bugzilla.redhat.com/show_bug.cgi?id=2528538
https://github.com/stefanberger/libtpms/commit/b1462888180d896af03cae0487e8d45009cc445e
https://github.com/stefanberger/libtpms/issues/614
https://github.com/stefanberger/libtpms/pull/613

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-04 18:18

Updated : 2026-09-08 19:08

NVD link : CVE-2026-85769

Mitre link : CVE-2026-85769

CVE.ORG link : CVE-2026-85769

JSON object : View

Products Affected

No product.

CWE

CWE-125

Out-of-bounds Read

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