{"id":"CVE-2026-12681","aliases":["DEBIAN-CVE-2026-12681","EUVD-2026-38641","GHSA-9r4w-jg96-92mv","GO-2026-5298","UBUNTU-CVE-2026-12681"],"status":"published","title":"Go-Attestation: Hash injection into trusted measurement list via unskipped SignatureHeaderSize vendor bytes in parseEfiSignatureList()","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.","severity":{"version":"4.0","score":8.9,"vector":"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00268,"percentile":0.1918,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-1285","CWE-20"],"published":"2026-06-12T15:04:43Z","modified":"2026-10-28T02:30:36Z","fixes":[{"ecosystem":"Go","package":"github.com/google/go-attestation","fixed_in":["0.6.1"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"golang-github-google-go-attestation","fixed_in":["0.6.1-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/google/go-attestation","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.6.0"},{"fixed":"0.6.1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"golang-github-google-go-attestation","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.6.1-1"}]}],"versions":["0.5.1-1","0.5.1-2","0.6.0-1","0.6.0-1~bpo13+1"]},{"source":"osv","ecosystem":"Go","package":"github.com/google/go-attestation","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.6.1"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/google/go-attestation","ranges":[{"type":"SEMVER","events":[{"introduced":"0"}]}]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"golang-github-google-go-attestation","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.6.0-1","0.6.1-5"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"golang-github-google-go-attestation","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.5.1-2","0.6.0-1"]}],"products":[{"vendor":"google","product":"go-attestation"},{"vendor":"google llc","product":"go-attestation"}],"references":[{"url":"https://github.com/google/go-attestation/security/advisories/GHSA-9r4w-jg96-92mv","tags":["advisory","web","report"]},{"url":"https://github.com/google/go-attestation/commit/b6e905e7ae52937f02b5ca494dd1c6a3ac7a1003","tags":["fix","web","report"]},{"url":"https://github.com/google/go-attestation/releases/tag/v0.6.1","tags":["web","report"]},{"url":"https://github.com/google/go-attestation/pull/502","tags":["web","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12681","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-9r4w-jg96-92mv"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12681.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-12681","tags":["advisory"]},{"url":"https://github.com/google/go-attestation","tags":["package"]},{"url":"https://github.com/google/go-attestation/releases/tag/v0.6.0","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2026-12681","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-12681","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-12681","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.","status":"published","published":"2026-06-24T00:49:13.5Z","modified":"2026-06-24T12:57:35.436Z","cvss":[{"version":"4.0","score":8.9,"vector":"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","level":"high","assessor":"cna"}],"cwes":["CWE-1285"],"updated_at":"2026-11-02T14:19:47.998488Z"}],"euvd":[{"id":"EUVD-2026-38641","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.","status":"published","published":"2026-06-24T00:49:13Z","modified":"2026-06-24T12:57:35Z","cvss":[{"version":"4.0","score":8.9,"vector":"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","level":"high"}],"updated_at":"2026-11-02T18:20:31.123469Z"}],"ghsa":[{"id":"GHSA-9r4w-jg96-92mv","title":"Go-Attestation: Hash injection into trusted measurement list via unskipped SignatureHeaderSize vendor bytes in parseEfiSignatureList()","description":"## Summary\n\n`parseEfiSignatureList()` in `attest/internal/events.go` does not skip\n`SignatureHeaderSize` vendor bytes before reading `EFI_SIGNATURE_LIST`\nsignature entries, violating UEFI specification section 31.4.1.\n\n## Impact\n\nFor `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.\n\n## Root Cause\n\nAfter `binary.Read(\u0026signatures.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.\n\n## Affected versions\n\nAll versions through commit `f877374` (2026-05-15).\n\n## Fix\n\nPull request: https://github.com/google/go-attestation/pull/502\n\n- Add bound check: `SignatureHeaderSize` must not exceed remaining list space\n- Skip `SignatureHeaderSize` bytes before both entry loops\n- Regression test: `TestParseEfiSignatureListNonZeroSignatureHeaderSize`","status":"published","published":"2026-06-12T15:04:43Z","modified":"2026-08-28T20:48:41Z","cvss":[{"version":"4.0","score":8.9,"vector":"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","level":"high"},{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"medium"}],"cwes":["CWE-20","CWE-1285"],"updated_at":"2026-11-02T14:41:08.084849Z"}],"nvd":[{"id":"CVE-2026-12681","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.","status":"published","published":"2026-06-24T02:16:28.06Z","modified":"2026-10-25T23:10:00.167Z","cvss":[{"version":"4.0","score":8.9,"vector":"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","level":"high","assessor":"secondary"}],"cwes":["CWE-1285"],"updated_at":"2026-11-02T14:12:25.288279Z"}],"osv":[{"id":"CVE-2026-12681","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.","status":"published","published":"2026-06-24T00:49:13.5Z","modified":"2026-10-28T02:30:36.937803307Z","cvss":[{"version":"4.0","score":8.9,"vector":"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","level":"high"}],"cwes":["CWE-1285"],"updated_at":"2026-11-02T15:44:57.354194Z"},{"id":"DEBIAN-CVE-2026-12681","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.","status":"published","published":"2026-06-24T02:16:28.06Z","modified":"2026-10-26T11:47:27.916439342Z","cvss":[{"version":"4.0","score":8.9,"vector":"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","level":"high"}],"updated_at":"2026-11-02T15:45:51.374409Z"},{"id":"GHSA-9r4w-jg96-92mv","title":"Go-Attestation: Hash injection into trusted measurement list via unskipped SignatureHeaderSize vendor bytes in parseEfiSignatureList()","description":"## Summary\n\n`parseEfiSignatureList()` in `attest/internal/events.go` does not skip\n`SignatureHeaderSize` vendor bytes before reading `EFI_SIGNATURE_LIST`\nsignature entries, violating UEFI specification section 31.4.1.\n\n## Impact\n\nFor `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.\n\n## Root Cause\n\nAfter `binary.Read(\u0026signatures.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.\n\n## Affected versions\n\nAll versions through commit `f877374` (2026-05-15).\n\n## Fix\n\nPull request: https://github.com/google/go-attestation/pull/502\n\n- Add bound check: `SignatureHeaderSize` must not exceed remaining list space\n- Skip `SignatureHeaderSize` bytes before both entry loops\n- Regression test: `TestParseEfiSignatureListNonZeroSignatureHeaderSize`","status":"published","published":"2026-06-12T15:04:43Z","modified":"2026-09-12T05:15:04.693981733Z","cvss":[{"version":"3.1","score":6.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N","level":"medium"},{"version":"4.0","score":8.9,"vector":"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","level":"high"}],"cwes":["CWE-1285","CWE-20"],"updated_at":"2026-11-02T15:46:44.225359Z"},{"id":"UBUNTU-CVE-2026-12681","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.","status":"published","published":"2026-06-24T02:16:00Z","modified":"2026-10-17T12:58:05.012102133Z","cvss":[{"version":"4.0","score":8.9,"vector":"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","level":"high"}],"updated_at":"2026-11-02T16:56:00.592716Z"},{"id":"GO-2026-5298","title":"Go-Attestation: Hash injection into trusted measurement list via unskipped SignatureHeaderSize vendor bytes in parseEfiSignatureList() in github.com/google/go-attestation","description":"Go-Attestation: Hash injection into trusted measurement list via unskipped SignatureHeaderSize vendor bytes in parseEfiSignatureList() in github.com/google/go-attestation","status":"published","published":"2026-06-25T18:43:19Z","modified":"2026-08-30T02:10:50.604598602Z","updated_at":"2026-11-02T15:47:02.556545Z"}]}}