{"id":"CVE-2026-43020","state":"PUBLISHED","title":"Bluetooth: MGMT: validate LTK enc_size on load","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: MGMT: validate LTK enc_size on load\n\nLoad Long Term Keys stores the user-provided enc_size and later uses\nit to size fixed-size stack operations when replying to LE LTK\nrequests. An enc_size larger than the 16-byte key buffer can therefore\noverflow the reply stack buffer.\n\nReject oversized enc_size values while validating the management LTK\nrecord so invalid keys never reach the stored key state.","publishedAt":"2026-05-01T14:15:23.699Z","updatedAt":"2026-05-11T22:16:09.294Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"0f37d1e65c6d71ad94ccfb5c602163c525db789d","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"257cdb960d8ff6d60bb6461b03c814b6cf0c9e64","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"c34577f517b556fb6ca173d45bf7e766ae2564ce","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"f71695e81f4cb428f3c7e2138eae88199005b52c","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"82f342b3b006ca1d65f4890c05f2ec32fcb808b6","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"b8dbe9648d69059cfe3a28917bfbf7e61efd7f15","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/mgmt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.4","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.134","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/mgmt.c"]}],"references":["https://git.kernel.org/stable/c/0f37d1e65c6d71ad94ccfb5c602163c525db789d","https://git.kernel.org/stable/c/257cdb960d8ff6d60bb6461b03c814b6cf0c9e64","https://git.kernel.org/stable/c/c34577f517b556fb6ca173d45bf7e766ae2564ce","https://git.kernel.org/stable/c/f71695e81f4cb428f3c7e2138eae88199005b52c","https://git.kernel.org/stable/c/82f342b3b006ca1d65f4890c05f2ec32fcb808b6","https://git.kernel.org/stable/c/50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257","https://git.kernel.org/stable/c/40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009","https://git.kernel.org/stable/c/b8dbe9648d69059cfe3a28917bfbf7e61efd7f15"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43020.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43020","state":"PUBLISHED","datePublished":"2026-05-01T14:15:23.699Z","dateUpdated":"2026-05-11T22:16:09.294Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:55.975Z"},"containers":{"cna":{"title":"Bluetooth: MGMT: validate LTK enc_size on load","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: MGMT: validate LTK enc_size on load\n\nLoad Long Term Keys stores the user-provided enc_size and later uses\nit to size fixed-size stack operations when replying to LE LTK\nrequests. An enc_size larger than the 16-byte key buffer can therefore\noverflow the reply stack buffer.\n\nReject oversized enc_size values while validating the management LTK\nrecord so invalid keys never reach the stored key state."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"0f37d1e65c6d71ad94ccfb5c602163c525db789d","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"257cdb960d8ff6d60bb6461b03c814b6cf0c9e64","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"c34577f517b556fb6ca173d45bf7e766ae2564ce","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"f71695e81f4cb428f3c7e2138eae88199005b52c","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"82f342b3b006ca1d65f4890c05f2ec32fcb808b6","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009","versionType":"git"},{"version":"346af67b8d116f01ef696fd47959a55deb2db8b6","status":"affected","lessThan":"b8dbe9648d69059cfe3a28917bfbf7e61efd7f15","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/mgmt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.4","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.134","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/mgmt.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0f37d1e65c6d71ad94ccfb5c602163c525db789d"},{"url":"https://git.kernel.org/stable/c/257cdb960d8ff6d60bb6461b03c814b6cf0c9e64"},{"url":"https://git.kernel.org/stable/c/c34577f517b556fb6ca173d45bf7e766ae2564ce"},{"url":"https://git.kernel.org/stable/c/f71695e81f4cb428f3c7e2138eae88199005b52c"},{"url":"https://git.kernel.org/stable/c/82f342b3b006ca1d65f4890c05f2ec32fcb808b6"},{"url":"https://git.kernel.org/stable/c/50fb64defa72a3fecd0af1ca7c6b47b5c5c2b257"},{"url":"https://git.kernel.org/stable/c/40ba329e8b4cd2fb11b0caf5e6a543ceaebb6009"},{"url":"https://git.kernel.org/stable/c/b8dbe9648d69059cfe3a28917bfbf7e61efd7f15"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:16:09.294Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.1.168"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.6.134"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.12.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.4","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}