{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31772","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-03-09T15:48:24.140Z","datePublished":"2026-05-01T14:15:00.582Z","dateUpdated":"2026-05-11T22:15:30.859Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T22:15:30.859Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync\n\nhci_le_big_create_sync() uses DEFINE_FLEX to allocate a\nstruct hci_cp_le_big_create_sync on the stack with room for 0x11 (17)\nBIS entries.  However, conn->num_bis can hold up to HCI_MAX_ISO_BIS (31)\nentries — validated against ISO_MAX_NUM_BIS (0x1f) in the caller\nhci_conn_big_create_sync().  When conn->num_bis is between 18 and 31,\nthe memcpy that copies conn->bis into cp->bis writes up to 14 bytes\npast the stack buffer, corrupting adjacent stack memory.\n\nThis is trivially reproducible: binding an ISO socket with\nbc_num_bis = ISO_MAX_NUM_BIS (31) and calling listen() will\neventually trigger hci_le_big_create_sync() from the HCI command\nsync worker, causing a KASAN-detectable stack-out-of-bounds write:\n\n  BUG: KASAN: stack-out-of-bounds in hci_le_big_create_sync+0x256/0x3b0\n  Write of size 31 at addr ffffc90000487b48 by task kworker/u9:0/71\n\nFix this by changing the DEFINE_FLEX count from the incorrect 0x11 to\nHCI_MAX_ISO_BIS, which matches the maximum number of BIS entries that\nconn->bis can actually carry."}],"metrics":[{"cvssV3_1":{"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"}}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"],"versions":[{"version":"91d19383b7ed035e22165ae5c836e50bb9f95fbe","lessThan":"f5d446624345d309e7a4a1b27ea9f028d6a8c5d9","status":"affected","versionType":"git"},{"version":"42ecf1947135110ea08abeaca39741636f9a2285","lessThan":"aba0aea354015794e8312dd7efe726967e58aefe","status":"affected","versionType":"git"},{"version":"42ecf1947135110ea08abeaca39741636f9a2285","lessThan":"eaf32002ca7b1ba51c9f140991fd9febe6de79f0","status":"affected","versionType":"git"},{"version":"42ecf1947135110ea08abeaca39741636f9a2285","lessThan":"bc39a094730ce062fa034a529c93147c096cb488","status":"affected","versionType":"git"},{"version":"8958e1cee4e2eac1a5b825caa4dd96ce9ed975dd","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"],"versions":[{"version":"6.13","status":"affected"},{"version":"0","lessThan":"6.13","status":"unaffected","versionType":"semver"},{"version":"6.12.81","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.22","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19.12","lessThanOrEqual":"6.19.*","status":"unaffected","versionType":"semver"},{"version":"7.0","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.2","versionEndExcluding":"6.12.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.0"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11.11"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/f5d446624345d309e7a4a1b27ea9f028d6a8c5d9"},{"url":"https://git.kernel.org/stable/c/aba0aea354015794e8312dd7efe726967e58aefe"},{"url":"https://git.kernel.org/stable/c/eaf32002ca7b1ba51c9f140991fd9febe6de79f0"},{"url":"https://git.kernel.org/stable/c/bc39a094730ce062fa034a529c93147c096cb488"}],"title":"Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync","x_generator":{"engine":"bippy-1.2.0"}}}}