CVE-2026-92701

Cocos AI: Intra-handshake attested TLS implementation is vulnerable to session-misbinding attacks for Intel TDX verifier path

Published Sep 18, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
Cocos AI is a confidential computing system for AI. In Cocos AI 0.8.2 and earlier, VerifTeeAttestation in the Intel TDX aTLS verifier receives an expected current-session value but does not apply it to TdQuoteBodyPolicy.ReportData before validating TDX QuoteV4 evidence. The verifier can consequently accept structurally valid evidence containing mismatched or reused REPORT_DATA for the current TLS session, causing the relying party to release application data or make a trust or authorization decision for an unrelated attestation context. This issue was fixed in Cocos AI 0.9.0 by removing the affected verifier path as part of the migration to post-handshake attestation.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Description Cocos AI is a confidential computing system for running AI workloads inside trusted execution environments. In versions up to and including 0.8.2, the intra-handshake attested TLS (aTLS) Intel TDX verification path does not copy the expected current-session freshness value into the TDX quote-body policy before quote validation, so structurally valid TDX QuoteV4 Evidence is accepted without checking that its REPORT_DATA field matches the reportData expected for the current session. A relying party using this path can therefore accept Evidence with a mismatched or reused reportData and release application data after the handshake, enabling session-misbinding to an unintended attestation context. The issue is fixed in version 0.9.0. Cocos AI is a confidential computing system for AI. In Cocos AI 0.8.2 and earlier, VerifTeeAttestation in the Intel TDX aTLS verifier receives an expected current-session value but does not apply it to TdQuoteBodyPolicy.ReportData before validating TDX QuoteV4 evidence. The verifier can consequently accept structurally valid evidence containing mismatched or reused REPORT_DATA for the current TLS session, causing the relying party to release application data or make a trust or authorization decision for an unrelated attestation context. This issue was fixed in Cocos AI 0.9.0 by removing the affected verifier path as part of the migration to post-handshake attestation.
Type Values Removed Values Added
Description trusted execution environments. In versions up to and including 0.8.2, the intra-handshake attested TLS (aTLS) Intel TDX verification path does not copy the expected current-session freshness value into the TDX quote-body policy before quote validation, so structurally valid TDX QuoteV4 Evidence is accepted without checking that its REPORT_DATA field matches the reportData expected for the current session. A relying party using this path can therefore accept Evidence with a mismatched or reused reportData and release application data after the handshake, enabling session-misbinding to an unintended attestation context. The issue is fixed in version 0.9.0. Cocos AI is a confidential computing system for running AI workloads inside trusted execution environments. In versions up to and including 0.8.2, the intra-handshake attested TLS (aTLS) Intel TDX verification path does not copy the expected current-session freshness value into the TDX quote-body policy before quote validation, so structurally valid TDX QuoteV4 Evidence is accepted without checking that its REPORT_DATA field matches the reportData expected for the current session. A relying party using this path can therefore accept Evidence with a mismatched or reused reportData and release application data after the handshake, enabling session-misbinding to an unintended attestation context. The issue is fixed in version 0.9.0.
Type Values Removed Values Added
First Time appeared Ultravioletrs
Ultravioletrs cocos
Vendors & Products Ultravioletrs
Ultravioletrs cocos
Type Values Removed Values Added
Description trusted execution environments. In versions up to and including 0.8.2, the intra-handshake attested TLS (aTLS) Intel TDX verification path does not copy the expected current-session freshness value into the TDX quote-body policy before quote validation, so structurally valid TDX QuoteV4 Evidence is accepted without checking that its REPORT_DATA field matches the reportData expected for the current session. A relying party using this path can therefore accept Evidence with a mismatched or reused reportData and release application data after the handshake, enabling session-misbinding to an unintended attestation context. The issue is fixed in version 0.9.0.
Title Cocos AI: Intra-handshake attested TLS implementation is vulnerable to session-misbinding attacks for Intel TDX verifier path
Weaknesses CWE-346
CWE-354
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 13, 2026, 8:08 PM
Reserved
Sep 16, 2026, 4:22 PM
Status
Deferred
Published
Sep 18, 2026, 6:18 PM
Modified
Oct 13, 2026, 9:19 PM