# CVE-2026-12681: Go-Attestation: Hash injection into trusted measurement list via unskipped SignatureHeaderSize vendor bytes in parseEfiSignatureList()

> Attackers can inject arbitrary hashes into TPM event logs, bypassing remote attestation verification in the go-attestation library.

- **Severity:** High 8.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 24 Jun 2026
- **Also known as:** DEBIAN-CVE-2026-12681, GHSA-9r4w-jg96-92mv, GO-2026-5298, MINI-7h4r-f7m3-3jw2, MINI-q3gf-2vwj-q2fv, UBUNTU-CVE-2026-12681

## What is CVE-2026-12681?

CVE-2026-12681 is a high-severity vulnerability in Google go-attestation, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Validation of Specified Index, Position, or Offset in Input vulnerability in Google go-attestation. parseEfiSignatureList() does not advance the buffer past vendor bytes before reading entries. For hashSHA256SigGUID lists, this allows attacker-controlled vendor header bytes to be appended to the trusted SHA256 hash list. A crafted TPM event log could inject arbitrary SHA256 hashes into the verifier's trusted measurement database, enabling a remote attestation verifier to accept a compromised boot state. This issue affects go-attestation: through 0.6.0.

Weakness: CWE-1285 (Improper Validation of Specified Index, Position, or Offset in Input)

## Which versions are affected by CVE-2026-12681?

3 open source packages ship an affected version, including github.com/google/go-attestation.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/google/go-attestation` | Go | All versions | None |
| `github.com/google/go-attestation` | Go | All versions | 0.6.1 |
| `github.com/google/go-attestation` | Go | All versions | 0.6.1 |

## How do I fix CVE-2026-12681?

Upgrade github.com/google/go-attestation to 0.6.1 or later.

## Is CVE-2026-12681 being exploited?

There is no known exploitation of CVE-2026-12681 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12681 and fix it if it is affected.

What it is: CVE-2026-12681 is a high-severity vulnerability in Google go-attestation, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-12681 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/google/go-attestation (Go): affected all versions; no fix listed
- github.com/google/go-attestation (Go): affected all versions; fixed in 0.6.1
- github.com/google/go-attestation (Go): affected all versions; fixed in 0.6.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-12681/ (Markdown: https://insights.sbomify.com/CVE-2026-12681/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12681
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12681
- OSV: https://osv.dev/vulnerability/CVE-2026-12681

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-12681/
Summaries are generated and may contain mistakes; the official description above is the record.