{"api_version":"1","generated_at":"2026-08-24T15:51:37+00:00","cve":"CVE-2026-68458","urls":{"html":"https://cve.report/CVE-2026-68458","api":"https://cve.report/api/cve/CVE-2026-68458.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-68458","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-68458"},"summary":{"title":"binder: cache secctx size before release zeroes it","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbinder: cache secctx size before release zeroes it\n\nbinder_transaction() bounds the scatter-gather buffer area with\nsg_buf_end_offset and subtracts the aligned LSM context size because\nthe secctx is written at the tail of that area.  The subtraction reads\nlsmctx.len, but that field has already been cleared by the time the\nline runs:\n\n    security_secid_to_secctx(secid, &lsmctx)   /* lsmctx.len set */\n    lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64))\n    extra_buffers_size += lsmctx_aligned_size\n    ...\n    security_release_secctx(&lsmctx)            /* memset zeroes len */\n    ...\n    sg_buf_end_offset = sg_buf_offset + extra_buffers_size\n                        - ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */\n\nsecurity_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len\nreads back as 0 and the subtraction contributes nothing, leaving\nsg_buf_end_offset too large by the aligned secctx size on every\ntransaction to a txn_security_ctx node.\n\nEach BINDER_TYPE_PTR object then derives buf_left = sg_buf_end_offset -\nsg_buf_offset as the sole upper bound on its copy, so the inflated end\noffset lets the copy run into the bytes that already hold the secctx.\n\nThe aligned size must therefore be cached before release rather than\nre-read from the now-cleared field.  Fix by caching it in\nlsmctx_aligned_size at function scope when it is first computed and\nsubtracting lsmctx_aligned_size instead of re-reading lsmctx.len after\nrelease.  Reuse the same value for the earlier buf_offset computation.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:18:15","updated_at":"2026-08-17 06:17:55"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/4257f45ee1fddd0558e77b62af8bb63fd87b2162","name":"https://git.kernel.org/stable/c/4257f45ee1fddd0558e77b62af8bb63fd87b2162","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1228926e1e4d605cc74d9e675558982a6f2cf446","name":"https://git.kernel.org/stable/c/1228926e1e4d605cc74d9e675558982a6f2cf446","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b34826e55aad3520ec813f1f367c11b24b29dc9f","name":"https://git.kernel.org/stable/c/b34826e55aad3520ec813f1f367c11b24b29dc9f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-68458","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68458","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fba89813ccf333d2bc4d5caea04cd5f3c39eb50 1228926e1e4d605cc74d9e675558982a6f2cf446 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fba89813ccf333d2bc4d5caea04cd5f3c39eb50 4257f45ee1fddd0558e77b62af8bb63fd87b2162 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6fba89813ccf333d2bc4d5caea04cd5f3c39eb50 b34826e55aad3520ec813f1f367c11b24b29dc9f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.14","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.14 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":"68458","cve":"CVE-2026-68458","epss":"0.001270000","percentile":"0.027780000","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/android/binder.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"1228926e1e4d605cc74d9e675558982a6f2cf446","status":"affected","version":"6fba89813ccf333d2bc4d5caea04cd5f3c39eb50","versionType":"git"},{"lessThan":"4257f45ee1fddd0558e77b62af8bb63fd87b2162","status":"affected","version":"6fba89813ccf333d2bc4d5caea04cd5f3c39eb50","versionType":"git"},{"lessThan":"b34826e55aad3520ec813f1f367c11b24b29dc9f","status":"affected","version":"6fba89813ccf333d2bc4d5caea04cd5f3c39eb50","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/android/binder.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.14"},{"lessThan":"6.14","status":"unaffected","version":"0","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":"6.18.40","versionStartIncluding":"6.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"6.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"6.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbinder: cache secctx size before release zeroes it\n\nbinder_transaction() bounds the scatter-gather buffer area with\nsg_buf_end_offset and subtracts the aligned LSM context size because\nthe secctx is written at the tail of that area.  The subtraction reads\nlsmctx.len, but that field has already been cleared by the time the\nline runs:\n\n    security_secid_to_secctx(secid, &lsmctx)   /* lsmctx.len set */\n    lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64))\n    extra_buffers_size += lsmctx_aligned_size\n    ...\n    security_release_secctx(&lsmctx)            /* memset zeroes len */\n    ...\n    sg_buf_end_offset = sg_buf_offset + extra_buffers_size\n                        - ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */\n\nsecurity_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len\nreads back as 0 and the subtraction contributes nothing, leaving\nsg_buf_end_offset too large by the aligned secctx size on every\ntransaction to a txn_security_ctx node.\n\nEach BINDER_TYPE_PTR object then derives buf_left = sg_buf_end_offset -\nsg_buf_offset as the sole upper bound on its copy, so the inflated end\noffset lets the copy run into the bytes that already hold the secctx.\n\nThe aligned size must therefore be cached before release rather than\nre-read from the now-cleared field.  Fix by caching it in\nlsmctx_aligned_size at function scope when it is first computed and\nsubtracting lsmctx_aligned_size instead of re-reading lsmctx.len after\nrelease.  Reuse the same value for the earlier buf_offset computation."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through binder IPC via ioctl(BINDER_WRITE_READ) on /dev/binder or binderfs with BC_TRANSACTION/BC_TRANSACTION_SG, requiring local access to the binder device; there is no network, Bluetooth, or physical bus path to binder_transaction().\nAC:L - This is a deterministic logic error, not a race: on every transaction to a txn_security_ctx node, security_release_secctx() zeroes lsmctx.len before sg_buf_end_offset is computed, so the attacker reliably gains extra scatter-gather space by crafting BINDER_TYPE_PTR objects.\nPR:L - binder_open() has no capability check; on Android any untrusted_app can open /dev/binder and send transactions, and on other systems binderfs is mountable from user namespaces, so only basic local user access is required—not real root.\nUI:N - Exploitation is driven entirely by the attacker's own binder client sending a crafted transaction; no victim user action such as opening a file, mounting a filesystem, or approving a prompt is required.\nS:U - Impact is overwriting kernel-managed LSM security context data within a binder transaction buffer to spoof caller identity for privilege escalation; this is standard local kernel/Android sandbox bypass, not a VM, hypervisor, or IOMMU boundary crossing.\nC:H - The inflated sg_buf_end_offset permits scatter-gather copies to overwrite the kernel-written secctx region—an out-of-bounds write relative to the intended SG boundary that can forge sender SELinux labels seen by privileged receivers, enabling unauthorized data access.\nI:H - Attacker-controlled user data from BINDER_TYPE_PTR copies overwrite the kernel-placed LSM security context string in the transaction buffer, directly corrupting integrity of trusted caller-identity metadata used for authorization decisions by privileged binder services.\nA:H - Kernel transaction-buffer corruption delivered to privileged Android framework/system services can crash critical binder receivers or destabilize the device; per kernel CVSS guidance, out-of-bounds writes and memory corruption in kernel IPC paths warrant High availability impact."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:39:07.025Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/1228926e1e4d605cc74d9e675558982a6f2cf446"},{"url":"https://git.kernel.org/stable/c/4257f45ee1fddd0558e77b62af8bb63fd87b2162"},{"url":"https://git.kernel.org/stable/c/b34826e55aad3520ec813f1f367c11b24b29dc9f"}],"title":"binder: cache secctx size before release zeroes it","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-68458","datePublished":"2026-08-15T05:51:18.975Z","dateReserved":"2026-07-30T09:28:09.395Z","dateUpdated":"2026-08-17T05:39:07.025Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:18:15","lastModifiedDate":"2026-08-17 06:17:55","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:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"68458","Ordinal":"1","Title":"binder: cache secctx size before release zeroes it","CVE":"CVE-2026-68458","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"68458","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nbinder: cache secctx size before release zeroes it\n\nbinder_transaction() bounds the scatter-gather buffer area with\nsg_buf_end_offset and subtracts the aligned LSM context size because\nthe secctx is written at the tail of that area.  The subtraction reads\nlsmctx.len, but that field has already been cleared by the time the\nline runs:\n\n    security_secid_to_secctx(secid, &lsmctx)   /* lsmctx.len set */\n    lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64))\n    extra_buffers_size += lsmctx_aligned_size\n    ...\n    security_release_secctx(&lsmctx)            /* memset zeroes len */\n    ...\n    sg_buf_end_offset = sg_buf_offset + extra_buffers_size\n                        - ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */\n\nsecurity_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len\nreads back as 0 and the subtraction contributes nothing, leaving\nsg_buf_end_offset too large by the aligned secctx size on every\ntransaction to a txn_security_ctx node.\n\nEach BINDER_TYPE_PTR object then derives buf_left = sg_buf_end_offset -\nsg_buf_offset as the sole upper bound on its copy, so the inflated end\noffset lets the copy run into the bytes that already hold the secctx.\n\nThe aligned size must therefore be cached before release rather than\nre-read from the now-cleared field.  Fix by caching it in\nlsmctx_aligned_size at function scope when it is first computed and\nsubtracting lsmctx_aligned_size instead of re-reading lsmctx.len after\nrelease.  Reuse the same value for the earlier buf_offset computation.","Type":"Description","Title":"binder: cache secctx size before release zeroes it"}]}}}