{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43405", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.007Z", "datePublished": "2026-05-08T14:21:45.581Z", "dateUpdated": "2026-08-05T12:27:48.288Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:27:48.288Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: Use u32 for non-negative values in ceph_monmap_decode()\n\nThis patch fixes unnecessary implicit conversions that change signedness\nof blob_len and num_mon in ceph_monmap_decode().\nCurrently blob_len and num_mon are (signed) int variables. They are used\nto hold values that are always non-negative and get assigned in\nceph_decode_32_safe(), which is meant to assign u32 values. Both\nvariables are subsequently used as unsigned values, and the value of\nnum_mon is further assigned to monmap->num_mon, which is of type u32.\nTherefore, both variables should be of type u32. This is especially\nrelevant for num_mon. If the value read from the incoming message is\nvery large, it is interpreted as a negative value, and the check for\nnum_mon > CEPH_MAX_MON does not catch it. This leads to the attempt to\nallocate a very large chunk of memory for monmap, which will most likely\nfail. In this case, an unnecessary attempt to allocate memory is\nperformed, and -ENOMEM is returned instead of -EINVAL." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable decoder processes CEPH_MSG_MON_MAP data received over the Ceph monitor TCP connection from a remote peer.\nAC:L - Triggering requires sending a single malformed monmap with a large u32 num_mon value; there is no race or condition outside the attacker's control once they control the monitor-side message stream.\nPR:N - The attacker needs no privileges on the vulnerable host; a malicious or compromised Ceph monitor endpoint can supply the crafted network message.\nUI:N - Although Ceph clients are initially created by mount or RBD setup, monitor map updates are received asynchronously over an established session and do not require further victim action.\nS:U - The impact remains within the kernel/Ceph client security authority and does not cross a VM, sandbox, or hardware isolation boundary.\nC:N - The signedness bug causes an oversized allocation attempt that fails; the investigated path does not expose kernel memory or create a read primitive.\nI:N - The allocation is overflow-safe and fails before the monmap is installed or populated, so there is no demonstrated memory corruption or data modification primitive.\nA:H - A crafted monmap can repeatedly force huge kernel allocation attempts and prevent the client from obtaining or refreshing a valid monitor map, denying Ceph storage availability in affected deployments." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ceph/mon_client.c" ], "versions": [ { "version": "a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c", "lessThan": "ee5588e2bc41acb73f6676c0520420c107cd0140", "status": "affected", "versionType": "git" }, { "version": "a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c", "lessThan": "86f7060cd638d6eb042e8ed780fb83a59ca0dcb3", "status": "affected", "versionType": "git" }, { "version": "a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c", "lessThan": "5f2806684b05bd24d05c091083b8e2517ba8ffac", "status": "affected", "versionType": "git" }, { "version": "a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c", "lessThan": "b268984ae88cb0dcd7a8e8263962c748448e26e8", "status": "affected", "versionType": "git" }, { "version": "a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c", "lessThan": "ba0a4df8c563536857dcbf7b4dbd0f2a15f57ace", "status": "affected", "versionType": "git" }, { "version": "a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c", "lessThan": "08bc6173fd611ad5a40f472bf5f15b92aea0fe40", "status": "affected", "versionType": "git" }, { "version": "a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c", "lessThan": "770444611f047dbfd4517ec0bc1b179d40c2f346", "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/mon_client.c" ], "versions": [ { "version": "5.11", "status": "affected" }, { "version": "0", "lessThan": "5.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.203", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.19", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.9", "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": "5.15.203" }, { "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" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ee5588e2bc41acb73f6676c0520420c107cd0140" }, { "url": "https://git.kernel.org/stable/c/86f7060cd638d6eb042e8ed780fb83a59ca0dcb3" }, { "url": "https://git.kernel.org/stable/c/5f2806684b05bd24d05c091083b8e2517ba8ffac" }, { "url": "https://git.kernel.org/stable/c/b268984ae88cb0dcd7a8e8263962c748448e26e8" }, { "url": "https://git.kernel.org/stable/c/ba0a4df8c563536857dcbf7b4dbd0f2a15f57ace" }, { "url": "https://git.kernel.org/stable/c/08bc6173fd611ad5a40f472bf5f15b92aea0fe40" }, { "url": "https://git.kernel.org/stable/c/770444611f047dbfd4517ec0bc1b179d40c2f346" } ], "title": "libceph: Use u32 for non-negative values in ceph_monmap_decode()", "x_generator": { "engine": "bippy-1.2.0" } } } }