{"id":"CVE-2026-112377","kind":"vulnerability","aliases":["CVE-2026-112377"],"related":[],"title":"attested-tls-poc: attestation evidence not bound to TLS, enabling relay impersonation","description":"CCC Attestation SIG attested-tls-poc through commit 731ca82 fails to bind early attestation Evidence to the TLS connection, allowing attackers to relay valid Evidence from a genuine attester. Attackers holding an extracted attested TLS private key can forward the relying party's nonce to a genuine attester and replay its Evidence to impersonate the attested workload and intercept data.","summary":"CCC Attestation SIG's attested-tls-poc, a demo of attestation inside the TLS handshake, does not bind early attestation Evidence to the TLS connection. An attacker with an extracted attested-TLS private key can relay the relying party's nonce to a genuine attester, replay its Evidence, impersonate the attested workload and intercept data. The maintainers marked the PoC as vulnerable and have not shipped a fix.","severity":"critical","cvss":9.1,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"attested-tls-poc","fixed":[],"affected":"<= 731ca82ed533fc7a1092be980887ae2e34261da2","ecosystem":"github"}],"ecosystems":[],"tags":["attested-tls","confidential-computing","package","proof-of-concept","tee-workloads"],"not_affected_if":["does-not-use-attested-tls-poc","no-intra-handshake-attestation"],"how_to_check":"Check whether you use or copied code from CCC-Attestation/attested-tls-poc (Docker recipes, its mbedtls fork, Veraison/Parsec components): run 'git log' or inspect your vendored commit and compare it to 731ca82ed533fc7a1092be980887ae2e34261da2. Any build at or before that commit is affected. Also check whether your own attested-TLS design signs only a nonce (and/or the server public key) in the Evidence without binding to the handshake.","fix":"No fixed version or commit as of 2026-10-23; the repo is a proof-of-concept and is declared vulnerable. Do not use it in production. Mitigation: bind Evidence to the TLS session (for example via a TLS exporter value or handshake-transcript secret) as discussed in the intra-handshake.fail work, and protect or rotate attested-TLS private keys that may have been extracted.","status":"open","published_at":"2026-10-19T18:17:05+00:00","first_seen_at":"2026-10-23T21:57:18+00:00","triaged_at":"2026-10-23T22:39:56+00:00","updated_at":"2026-10-23T23:24:25+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-23T22:39:56Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"attested-tls-poc: attestation evidence not bound to TLS, enabling relay impersonation","impact":"high","summary":"The attested-tls-poc proof-of-concept fails to bind early attestation evidence to the TLS connection. An attacker holding an extracted attested TLS private key can relay a genuine attester's evidence and impersonate the attested workload to intercept data.","category":"package","who_cares":["attested-tls","confidential-computing","tee-workloads"],"confidence":0.6,"needs_auth":"unknown","worst_case":"attacker impersonates attested workload and intercepts its data","analyst_note":"Check the NVD entry and the CCC Attestation SIG repository for a fixed commit or version, and whether any downstream project ships this code beyond a proof-of-concept.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["does-not-use-attested-tls-poc"],"user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"critical"},"cost_usd":0.000481,"input_tokens":2970,"output_tokens":369,"severity_before":"critical"},"analyst_status":"done","analyst_note":"Check the NVD entry and the CCC Attestation SIG repository for a fixed commit or version, and whether any downstream project ships this code beyond a proof-of-concept.","search":"'-112377':16A,19A '-2026':15A,18A '731ca82':117C 'allow':128C 'attack':65B,129C,138C 'attest':2A,5A,25B,39B,43B,49B,58B,70B,84B,90B,109C,112C,122C,137C,142C,156C,164C 'attested':21A 'attested-tl':24B,69B 'attested-tls-poc':1A,20A,42B,111C 'bind':56B,120C 'bound':8A 'ccc':38B,108C 'commit':116C 'comput':29B 'concept':34B 'confidenti':28B 'confidential-comput':27B 'connect':63B,127C 'cve':14A,17A 'data':94B,168C 'demo':47B 'earli':57B,121C 'enabl':11A 'evid':6A,59B,87B,123C,133C,160C 'extract':68B,141C 'fail':118C 'fix':107B 'forward':147C 'genuin':83B,136C,155C 'handshak':53B 'hold':139C 'imperson':13A,88B,162C 'insid':50B 'intercept':93B,167C 'key':73B,145C 'maintain':96B 'mark':97B 'nonc':80B,152C 'packag':30B 'parti':78B,150C 'poc':4A,23A,45B,99B,114C 'privat':72B,144C 'proof':32B 'proof-of-concept':31B 'relay':12A,75B,131C 'reli':77B,149C 'replay':85B,158C 'ship':105B 'sig':40B,110C 'tee':36B 'tee-workload':35B 'tls':3A,10A,22A,26B,44B,52B,62B,71B,113C,126C,143C 'valid':132C 'vulner':101B 'workload':37B,91B,165C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-19T18:17:05+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/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","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-112377","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-112377","severity":null,"published_at":"2026-10-19T18:17:05+00:00","modified_at":"2026-10-20T18:17:18+00:00","first_seen_at":"2026-10-23T21:57:18+00:00","fetched_at":"2026-10-23T22:28:57+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-112377:436","url":null,"severity":null,"published_at":"2026-10-23T23:24:25+00:00","modified_at":"2026-10-23T23:24:25+00:00","first_seen_at":"2026-10-23T23:24:25+00:00","fetched_at":"2026-10-23T23:24:25+00:00","note":"Primary: maintainers' PR #58 (merged 2026-07-17) declares the PoC vulnerable; no fix exists, the CVE is a disclosure of a design flaw in a demo repo. EUVD/GHSA list affected as <= commit 731ca82ed533fc7a1092be980887ae2e34261da2. Not exploited, no KEV, EPSS 0.18%. Related research (intra-handshake.fail, CVE-2026-33697) says other intra-handshake attestation designs share the binding weakness; I did not verify downstream shipping of this code. Severity left at critical per CNA CVSS 4.0 9.1, though real exposure is limited to anyone who copied this PoC."}],"documents":[{"id":1936,"url":"https://github.com/CCC-Attestation/attested-tls-poc/pull/58","title":"attested-tls-poc PR #58: Add proof of relay attacks (declares PoC vulnerable)","kind":"issue","source":"analyst","text":null,"published_at":null,"relation":"describes","confidence":null,"note":null},{"id":1937,"url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-104535","title":"EUVD-2026-104535 / GHSA-hqrh-qq2r-6h96","kind":"advisory","source":"analyst","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":null},{"id":1940,"url":"https://github.com/muhammad-usama-sardar/intra-handshake.fail","title":"intra-handshake.fail: formal analysis of attested TLS binding mechanisms","kind":"blog","source":"analyst","text":null,"published_at":null,"relation":"mentions","confidence":null,"note":null}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}