{"id":"CVE-2026-43406","state":"PUBLISHED","title":"libceph: prevent potential out-of-bounds reads in process_message_header()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: prevent potential out-of-bounds reads in process_message_header()\n\nIf the message frame is (maliciously) corrupted in a way that the\nlength of the control segment ends up being less than the size of the\nmessage header or a different frame is made to look like a message\nframe, out-of-bounds reads may ensue in process_message_header().\n\nPerform an explicit bounds check before decoding the message header.","publishedAt":"2026-05-08T14:21:46.246Z","updatedAt":"2026-10-19T19:16:28.625Z","severity":{"score":9.1,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"76ccf21a12c5f6d6790bc32c7da82446d877b2f4","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"75582aaa580c11aed4c7731cad6b068b700e7efb","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"50156622eb0888e62541d715a98584480a1bc7cb","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"dbd857a9e1e33ea71eaf3e211877027e533770d1","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"69fe5af33fa3806f398d21c081d73c66e5523bc2","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"035867ae6f18df0aeedb2a57a5b74091bd4e3fe8","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"69fb5d91bba44ecf7eb80530b85fa4fb028921d5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/messenger_v2.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.19","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","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/ceph/messenger_v2.c"]}],"references":["https://git.kernel.org/stable/c/76ccf21a12c5f6d6790bc32c7da82446d877b2f4","https://git.kernel.org/stable/c/75582aaa580c11aed4c7731cad6b068b700e7efb","https://git.kernel.org/stable/c/50156622eb0888e62541d715a98584480a1bc7cb","https://git.kernel.org/stable/c/dbd857a9e1e33ea71eaf3e211877027e533770d1","https://git.kernel.org/stable/c/69fe5af33fa3806f398d21c081d73c66e5523bc2","https://git.kernel.org/stable/c/035867ae6f18df0aeedb2a57a5b74091bd4e3fe8","https://git.kernel.org/stable/c/69fb5d91bba44ecf7eb80530b85fa4fb028921d5"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43406.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43406","state":"PUBLISHED","datePublished":"2026-05-08T14:21:46.246Z","dateUpdated":"2026-10-19T19:16:28.625Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:56.007Z"},"containers":{"cna":{"title":"libceph: prevent potential out-of-bounds reads in process_message_header()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: prevent potential out-of-bounds reads in process_message_header()\n\nIf the message frame is (maliciously) corrupted in a way that the\nlength of the control segment ends up being less than the size of the\nmessage header or a different frame is made to look like a message\nframe, out-of-bounds reads may ensue in process_message_header().\n\nPerform an explicit bounds check before decoding the message header."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"76ccf21a12c5f6d6790bc32c7da82446d877b2f4","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"75582aaa580c11aed4c7731cad6b068b700e7efb","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"50156622eb0888e62541d715a98584480a1bc7cb","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"dbd857a9e1e33ea71eaf3e211877027e533770d1","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"69fe5af33fa3806f398d21c081d73c66e5523bc2","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"035867ae6f18df0aeedb2a57a5b74091bd4e3fe8","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","status":"affected","lessThan":"69fb5d91bba44ecf7eb80530b85fa4fb028921d5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/messenger_v2.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.167","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.130","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.78","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.19","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","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/ceph/messenger_v2.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/76ccf21a12c5f6d6790bc32c7da82446d877b2f4"},{"url":"https://git.kernel.org/stable/c/75582aaa580c11aed4c7731cad6b068b700e7efb"},{"url":"https://git.kernel.org/stable/c/50156622eb0888e62541d715a98584480a1bc7cb"},{"url":"https://git.kernel.org/stable/c/dbd857a9e1e33ea71eaf3e211877027e533770d1"},{"url":"https://git.kernel.org/stable/c/69fe5af33fa3806f398d21c081d73c66e5523bc2"},{"url":"https://git.kernel.org/stable/c/035867ae6f18df0aeedb2a57a5b74091bd4e3fe8"},{"url":"https://git.kernel.org/stable/c/69fb5d91bba44ecf7eb80530b85fa4fb028921d5"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","baseScore":9.1,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable libceph messenger v2 path is reached by TCP data received from a Ceph peer, and the reproducer triggers it over the network against a kernel Ceph client.\nAC:L - The bug is deterministic: a peer sends a FRAME_TAG_MESSAGE frame with a control segment shorter than struct ceph_msg_header2 in msgr2 crc/non-secure mode. No race or attacker-uncontrolled timing condition is required.\nPR:N - The vulnerable read can occur during CEPH_CON_S_V2_HELLO or CEPH_CON_S_V2_AUTH before credentials are verified, so the network peer does not need authenticated privileges.\nUI:N - In a reasonable deployment with an already configured or reconnecting Ceph client, a malicious or spoofed Ceph peer can send the frame without further victim action.\nS:U - The impact is within the kernel/libceph client security scope and does not cross a VM, IOMMU, or other separate security authority boundary.\nC:H - The flaw is a slab out-of-bounds read of attacker-triggered kernel memory beyond a too-small control buffer. Following the required guidance, an out-of-bounds read that is not strictly limited to only a few bytes is scored High for confidentiality.\nI:N - The defect is an out-of-bounds read, and the investigated path does not provide an out-of-bounds write, memory corruption, or authenticated message dispatch that would directly modify data.\nA:H - The malformed network frame deterministically triggers a KASAN-detected slab out-of-bounds access in the ceph-msgr workqueue and can fault/disrupt the Ceph client connection. Repeated unauthenticated triggering can deny availability of kernel Ceph storage access."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:27:49.364Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.1.167"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.6.130"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.12.78"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.18.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.19.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-43406","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:17:09.082944Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:16:28.625Z"}}]}}}