{"api_version":"1","generated_at":"2026-08-25T15:58:50+00:00","cve":"CVE-2026-72151","urls":{"html":"https://cve.report/CVE-2026-72151","api":"https://cve.report/api/cve/CVE-2026-72151.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-72151","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72151"},"summary":{"title":"tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt\n\ntpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls\ncrypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret()\nwithout installing a completion callback, discards both return values,\nand immediately frees the kpp_request via kpp_request_free(). When the\nresolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE,\nkeembay-ocs), either operation returns -EINPROGRESS and the deferred\ncompletion worker dereferences the freed request.\n\nThe path fires automatically from the hwrng_fillfn kernel thread via\ntpm_get_random -> tpm2_get_random -> tpm2_start_auth_session ->\ntpm_buf_append_salt on every entropy poll, without any userland action.\n\nInstall crypto_req_done as the completion callback, wrap both KPP\noperations in crypto_wait_req(), and propagate errors to the caller.\nThe wait is a no-op for synchronous backends.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:21:32","updated_at":"2026-08-17 06:18:15"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"8.4","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"8.4","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":8.4,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/934d1cd40e2893bf7a041b54f6afd1c008d7a21c","name":"https://git.kernel.org/stable/c/934d1cd40e2893bf7a041b54f6afd1c008d7a21c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/73851a7c43dfa52d2ed9415889b33daf85da0ed9","name":"https://git.kernel.org/stable/c/73851a7c43dfa52d2ed9415889b33daf85da0ed9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/493333f167926c7adab8e7563e21ad71d8af84fa","name":"https://git.kernel.org/stable/c/493333f167926c7adab8e7563e21ad71d8af84fa","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/111e520efbe82b324bc42b1999b723c0619eea6d","name":"https://git.kernel.org/stable/c/111e520efbe82b324bc42b1999b723c0619eea6d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72151","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72151","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1085b8276bb4239daa7008f0dcd5c973e4bd690f 111e520efbe82b324bc42b1999b723c0619eea6d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1085b8276bb4239daa7008f0dcd5c973e4bd690f 934d1cd40e2893bf7a041b54f6afd1c008d7a21c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1085b8276bb4239daa7008f0dcd5c973e4bd690f 493333f167926c7adab8e7563e21ad71d8af84fa git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1085b8276bb4239daa7008f0dcd5c973e4bd690f 73851a7c43dfa52d2ed9415889b33daf85da0ed9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.10","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.10 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"72151","cve":"CVE-2026-72151","epss":"0.001820000","percentile":"0.081070000","score_date":"2026-08-17","updated_at":"2026-08-18 00:11:47"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/char/tpm/tpm2-sessions.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"111e520efbe82b324bc42b1999b723c0619eea6d","status":"affected","version":"1085b8276bb4239daa7008f0dcd5c973e4bd690f","versionType":"git"},{"lessThan":"934d1cd40e2893bf7a041b54f6afd1c008d7a21c","status":"affected","version":"1085b8276bb4239daa7008f0dcd5c973e4bd690f","versionType":"git"},{"lessThan":"493333f167926c7adab8e7563e21ad71d8af84fa","status":"affected","version":"1085b8276bb4239daa7008f0dcd5c973e4bd690f","versionType":"git"},{"lessThan":"73851a7c43dfa52d2ed9415889b33daf85da0ed9","status":"affected","version":"1085b8276bb4239daa7008f0dcd5c973e4bd690f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/char/tpm/tpm2-sessions.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.10"},{"lessThan":"6.10","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"6.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"6.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"6.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"6.10","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt\n\ntpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls\ncrypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret()\nwithout installing a completion callback, discards both return values,\nand immediately frees the kpp_request via kpp_request_free(). When the\nresolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE,\nkeembay-ocs), either operation returns -EINPROGRESS and the deferred\ncompletion worker dereferences the freed request.\n\nThe path fires automatically from the hwrng_fillfn kernel thread via\ntpm_get_random -> tpm2_get_random -> tpm2_start_auth_session ->\ntpm_buf_append_salt on every entropy poll, without any userland action.\n\nInstall crypto_req_done as the completion callback, wrap both KPP\noperations in crypto_wait_req(), and propagate errors to the caller.\nThe wait is a no-op for synchronous backends."}],"metrics":[{"cvssV3_1":{"baseScore":8.4,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable code is reached only via local kernel TPM/HWRNG paths (hwrng_fillfn kernel thread polling tpm_get_random, or local /dev/hwrng reads); there is no network, adjacent-radio, or physical-access entry point to tpm_buf_append_salt.\nAC:L - On affected builds (CONFIG_TCG_TPM2_HMAC plus an async ecdh-nist-p256 backend), the UAF is deterministically triggered each auth-session setup without winning a race; async KPP returns -EINPROGRESS and the completion worker later dereferences the already-freed kpp_request.\nPR:N - No attacker credentials are required: the hwrng kernel thread invokes tpm2_start_auth_session automatically on TPM RNG polls, and unprivileged local processes can also reach tpm_get_random via /dev/hwrng without root or namespaced admin capabilities.\nUI:N - Exploitation does not require any victim user action such as mounting a filesystem or opening a file; the bug fires from background kernel entropy collection and TPM session setup without interactive steps.\nS:U - Impact is confined to kernel memory integrity and availability on the same host; it is a standard kernel heap UAF, not a cross-boundary escape such as guest-to-host VM breakout or IOMMU/DMA bypass.\nC:H - Use-after-free of a kmalloc'd kpp_request lets an attacker influence freed heap contents and potentially obtain arbitrary kernel memory read primitives through heap grooming, not merely a bounded leak.\nI:H - The UAF corrupts kernel heap metadata/object lifetimes and can be leveraged for arbitrary write or control-flow hijack (privilege escalation), not just limited or transient data modification.\nA:H - The deferred crypto completion dereferences freed memory, causing kernel oops/panic or hang during normal TPM RNG polling, yielding complete loss of system availability on affected hardware."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:41:00.459Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/111e520efbe82b324bc42b1999b723c0619eea6d"},{"url":"https://git.kernel.org/stable/c/934d1cd40e2893bf7a041b54f6afd1c008d7a21c"},{"url":"https://git.kernel.org/stable/c/493333f167926c7adab8e7563e21ad71d8af84fa"},{"url":"https://git.kernel.org/stable/c/73851a7c43dfa52d2ed9415889b33daf85da0ed9"}],"title":"tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-72151","datePublished":"2026-08-15T05:53:22.196Z","dateReserved":"2026-08-09T03:40:39.908Z","dateUpdated":"2026-08-17T05:41:00.459Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:21:32","lastModifiedDate":"2026-08-17 06:18:15","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":2.5,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"72151","Ordinal":"1","Title":"tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_app","CVE":"CVE-2026-72151","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"72151","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: tpm2-sessions: wait for async KPP completion in tpm_buf_append_salt\n\ntpm_buf_append_salt() in drivers/char/tpm/tpm2-sessions.c calls\ncrypto_kpp_generate_public_key() and crypto_kpp_compute_shared_secret()\nwithout installing a completion callback, discards both return values,\nand immediately frees the kpp_request via kpp_request_free(). When the\nresolved ecdh-nist-p256 KPP backend is asynchronous (atmel-ecc, HPRE,\nkeembay-ocs), either operation returns -EINPROGRESS and the deferred\ncompletion worker dereferences the freed request.\n\nThe path fires automatically from the hwrng_fillfn kernel thread via\ntpm_get_random -> tpm2_get_random -> tpm2_start_auth_session ->\ntpm_buf_append_salt on every entropy poll, without any userland action.\n\nInstall crypto_req_done as the completion callback, wrap both KPP\noperations in crypto_wait_req(), and propagate errors to the caller.\nThe wait is a no-op for synchronous backends.","Type":"Description","Title":"tpm: tpm2-sessions: wait for async KPP completion in tpm_buf_app"}]}}}