CVE-2026-12681Published

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 all…

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-12681

Published

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.

Source published: 24 Jun 2026 00:49:13 UTC
Source modified: 24 Jun 2026 12:57:35 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

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CVSS 4.0 · 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

euvd · EUVD-2026-38641

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Jun 24, 2026, 12:49:13 AM

dateUpdated: Jun 24, 2026, 12:57:35 PM

Source published: Jun 24, 2026, 12:49:13 AM (timezone not stated)
Source modified: Jun 24, 2026, 12:57:35 PM (timezone not stated)
Observed here: 7 Nov 2026 05:27:10 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 4.0 · 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

nvd · CVE-2026-12681

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Awaiting Analysis

Weakness classifications: CWE-1285

Original publisher date fields

published: 2026-06-24T02:16:28.060

lastModified: 2026-10-25T23:10:00.167

Source published: 24 Jun 2026 02:16:28 UTC
Source modified: 25 Oct 2026 23:10:00 UTC
Observed here: 27 Oct 2026 06:23:27 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

osv · GHSA-9r4w-jg96-92mv

Published

## Summary `parseEfiSignatureList()` in `attest/internal/events.go` does not skip `SignatureHeaderSize` vendor bytes before reading `EFI_SIGNATURE_LIST` signature entries, violating UEFI specification section 31.4.1. ## Impact For `hashSHA256SigGUID` lists, attacker-controlled vendor header bytes are appended directly to the trusted SHA256 hash list. A crafted TPM event log can inject arbitrary SHA256 hashes into the verifier's trusted measurement database, allowing a remote attestation verifier to accept a compromised boot state as legitimate — breaking the core integrity guarantee of remote attestation. ## Root Cause After `binary.Read(&signatures.Header)` reads 28 bytes, `buf` points to the start of the `SignatureHeaderSize` vendor bytes. Both entry loops start at `sigOffset := 0` instead of `sigOffset := SignatureHeaderSize`, causing vendor bytes to be read as signature entries. ## Affected versions All versions through commit `f877374` (2026-05-15). ## Fix Pull request: https://github.com/google/go-attestation/pull/502 - Add bound check: `SignatureHeaderSize` must not exceed remaining list space - Skip `SignatureHeaderSize` bytes before both entry loops - Regression test: `TestParseEfiSignatureListNonZeroSignatureHeaderSize`

Source published: 12 Jun 2026 15:04:43 UTC
Source modified: 12 Sep 2026 05:15:04 UTC
Observed here: 24 Oct 2026 13:19:41 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

CVSS_V4 · 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Publisher rating · HIGH

osv · GO-2026-5298

Published

Go-Attestation: Hash injection into trusted measurement list via unskipped SignatureHeaderSize vendor bytes in parseEfiSignatureList() in github.com/google/go-attestation

Source published: 25 Jun 2026 18:43:19 UTC
Source modified: 30 Aug 2026 02:10:50 UTC
Observed here: 24 Oct 2026 13:19:41 UTC
Source terms: OSV · upstream source license applies

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.