Info Leak in TCG TPM 2.0 Reference Code Enables Attestation Key Forgery
CVSS 3.1
7.9high
EPSS
<1%p12
Published
()
Modified
AI analysis
An information-leakage flaw in the Trusted Computing Group's TPM 2.0 reference code (tracked by TCG as VRT0010 and by CERT/CC as VU#431093) allows a local attacker with elevated privileges to obtain a credential from a TPM-aware certificate authority for a falsified TPM key. It is triggered locally on systems whose TPM runs code derived from the TCG reference implementation when the attacker manipulates key-attestation flows for keys such as an Attestation Key, DevID Key, or TLS authentication key. With the fraudulently issued credential, the attacker can falsify other TPM 2.0 attestations with that key, undermining device-identity and attestation guarantees. Any deployment of the TCG TPM 2.0 reference code - including commercial TPM chips, firmware TPMs, and TPM-aware CA/attestation infrastructure - is potentially affected; the available data does not specify version ranges. No exploitation has been observed: there is no public proof-of-concept, the issue is not in CISA's KEV, and EPSS estimates only a ~0.2% chance of exploitation in the next 30 days.
What to do: Track TCG VRT0010/VU#431093 and apply TPM/BIOS firmware updates from your PC or TPM vendor as they become available; Microsoft's August 2026 Patch Tuesday batch (398 CVEs) is among related releases, so verify whether your platform's TPM fix shipped there. Prioritize environments that use TPM key attestation with a CA (EK/AK, DevID, or TLS client certificates) and restrict local administrative privileges until patched. Audit attestation credentials issued by TPM-aware CAs for keys that may have been falsified.
Affected
Trusted Computing Group (TCG) TPM 2.0 reference code (and TPM implementations derived from it)
—
Estimated exposure
masshundreds of millions of devices (TPM 2.0 is standard on modern PCs, and many TPM chips and firmware TPMs derive from the TCG reference code) — TPM 2.0 is effectively mandatory on current Windows PCs and the TCG reference implementation underlies many commercial and firmware TPMs, though practical exploitation additionally requires a TPM-aware CA attestation workflow and local…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description
An information leakage vulnerability was reported in the TCG TPM 2.0 reference code that could allow a local attacker with elevated privileges to obtain a credential from a TPM-aware CA for a falsified TPM key (such as an Attestation Key, DevID Key or TLS authentication key) and falsify other TPM 2.0 attestations with this key. See also TCG VRT0010.
Tenable reports Microsoft's August 2026 Patch Tuesday addresses 398 CVEs including three zero-days, one exploited in the wild (CVE-2026-68820).
Microsoft patched 398 CVEs in its August 2026 Patch Tuesday release, with 42 rated critical, 355 important, and one moderate, and three zero-days among them. One zero-day is confirmed as exploited in the wild. The release covers components including .NET, .NET Framework, Active Directory Certificate Services (AD CS), Azure services, and Windows. Tenable's count omits two CVEs assigned by MITRE, CVE-2026-6726 and CVE-2026-6727.
CERT/CC discloses two TPM 2.0 reference code flaws allowing RSA key decryption and forged TPM attestations via crafted commands.
CERT/CC published VU#431093 covering two vulnerabilities in the TCG TPM 2.0 reference implementation: CVE-2026-6726 (information leakage via falsified TPM keys) and CVE-2026-6727 (timing side-channel in RSA OAEP decryption). An attacker with privileged access to a TPM command interface could send crafted TPM commands to decrypt ciphertexts for affected TPM-managed RSA keys, including the RSA Endorsement Key, or obtain credentials enabling forged TPM 2.0 attestations. Remediation is tracked in TCGVRT010 and TCGVRT0011.