{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43304","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-01T14:12:56.000Z","datePublished":"2026-05-08T13:11:24.264Z","dateUpdated":"2026-08-05T12:27:09.910Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:27:09.910Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: define and enforce CEPH_MAX_KEY_LEN\n\nWhen decoding the key, verify that the key material would fit into\na fixed-size buffer in process_auth_done() and generally has a sane\nlength.\n\nThe new CEPH_MAX_KEY_LEN check replaces the existing check for a key\nwith no key material which is a) not universal since CEPH_CRYPTO_NONE\nhas to be excluded and b) doesn't provide much value since a smaller\nthan needed key is just as invalid as no key -- this has to be handled\nelsewhere anyway."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable path is reached by TCP data received from a Ceph msgr2 peer during monitor/OSD authentication, through sock_recvmsg() to process_auth_done(). A malicious or compromised Ceph endpoint can supply the crafted AUTH_DONE payload over the network.\nAC:L - Once the attacker can act as the responding Ceph peer, the oversized decoded session key is a deterministic protocol field and no race or hard-to-control condition is required. The stack overwrite follows directly from the key length accepted before the fix.\nPR:N - The attacker needs no local privileges on the victim kernel; the code is reached during the network authentication handshake before the connection is fully established. Even though CephX payloads are cryptographic, a malicious configured/compromised peer can trigger the path remotely.\nUI:N - No interactive victim action is required once the vulnerable client connects to the Ceph peer as part of normal operation. The malicious AUTH_DONE response is processed automatically by the kernel client.\nS:U - The impact is compromise or crash of the same kernel/client security authority that contains the vulnerable libceph code. This is not a VM escape, IOMMU bypass, or other cross-scope boundary violation.\nC:H - The bug is attacker-controlled kernel stack memory corruption from copying an unchecked session key into a fixed-size stack buffer. Such memory corruption can reasonably be leveraged for sensitive kernel memory disclosure.\nI:H - The unchecked memcpy can overwrite adjacent kernel stack state with attacker-controlled key bytes. This is an out-of-bounds write with plausible control-flow or data corruption impact.\nA:H - The stack overflow can corrupt kernel execution state and cause an oops or panic. Even without full exploitation, a malicious peer can crash the client kernel."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/crypto.c","net/ceph/crypto.h","net/ceph/messenger_v2.c"],"versions":[{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","lessThan":"6405e8c680974bb74e2c98d5249fb52c7b12a6c6","status":"affected","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","lessThan":"8d745d38c88ecbed95f6b2b39857bf89f35a3244","status":"affected","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","lessThan":"e1dc45d97975f9db65694d234fbddf1915176e16","status":"affected","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","lessThan":"1b275bd49e58752efb83767a5d1aed41356c5e64","status":"affected","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","lessThan":"c1a0f5f1e5e7e98c36a362ec3d1fcfd9932931ed","status":"affected","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","lessThan":"d82467c07b03a27c3c5469b62bb3b726305a80bb","status":"affected","versionType":"git"},{"version":"cd1a677cad994021b19665ed476aea63f5d54f31","lessThan":"ac431d597a9bdfc2ba6b314813f29a6ef2b4a3bf","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/ceph/crypto.c","net/ceph/crypto.h","net/ceph/messenger_v2.c"],"versions":[{"version":"5.11","status":"affected"},{"version":"0","lessThan":"5.11","status":"unaffected","versionType":"semver"},{"version":"5.15.202","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.165","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.128","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.75","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.16","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19.6","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":"5.11","versionEndExcluding":"5.15.202"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.1.165"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.6.128"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.18.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.19.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"7.0"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/6405e8c680974bb74e2c98d5249fb52c7b12a6c6"},{"url":"https://git.kernel.org/stable/c/8d745d38c88ecbed95f6b2b39857bf89f35a3244"},{"url":"https://git.kernel.org/stable/c/e1dc45d97975f9db65694d234fbddf1915176e16"},{"url":"https://git.kernel.org/stable/c/1b275bd49e58752efb83767a5d1aed41356c5e64"},{"url":"https://git.kernel.org/stable/c/c1a0f5f1e5e7e98c36a362ec3d1fcfd9932931ed"},{"url":"https://git.kernel.org/stable/c/d82467c07b03a27c3c5469b62bb3b726305a80bb"},{"url":"https://git.kernel.org/stable/c/ac431d597a9bdfc2ba6b314813f29a6ef2b4a3bf"}],"title":"libceph: define and enforce CEPH_MAX_KEY_LEN","x_generator":{"engine":"bippy-1.2.0"}}}}