CVE-2026-12681Network attack vector

Attestation bypass via trusted hash injection

Published Jun 24, 2026 · Updated Jun 24, 2026

Improper offset validation in Google go-attestation 0.6.0 and earlier allows remote attackers to pass compromised boot states as trusted. parseEfiSignatureList() reads EFI_SIGNATURE_LIST entries before skipping SignatureHeaderSize vendor bytes, placing attacker-controlled bytes in the trusted SHA256 hash list. Exploitation requires a verifier to process a crafted TPM event log, after which injected hashes make unauthorized boot measurements appear legitimate.

CVSS severity8.9
High
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper offset validation in Google go-attestation 0.6.0 and earlier allows remote attackers to pass compromised boot states as trusted. parseEfiSignatureList() reads EFI_SIGNATURE_LIST entries before skipping SignatureHeaderSize vendor bytes, placing attacker-controlled bytes in the trusted SHA256 hash list. Exploitation requires a verifier to process a crafted TPM event log, after which injected hashes make unauthorized boot measurements appear legitimate.

The record

CVE
CVE-2026-12681
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
Go standard library
Product
go-attestation
Classifications
CWE-20, CWE-1285, T1553
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=0.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go standard library · go-attestationversion=0 <=0.6.0

Published CVSS scores

8.9Google Inc.CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N
6.8GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-1285Improper Validation of Specified Index, Position, or Offset in Input
T1553Subvert Trust Controls

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo