CVE-2026-68433 (GCVE-0-2026-68433)
Vulnerability from cvelistv5
Published
2026-08-12 00:07
Modified
2026-08-19 16:35
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
libceph: bound get_version reply decode to front len
handle_get_version_reply() uses msg->front_alloc_len as the decode
boundary for MON_GET_VERSION_REPLY. That is the size of the reused
reply buffer, not the number of bytes actually received.
A truncated reply can therefore pass ceph_decode_need() and decode the
second u64 from stale tail bytes left in the buffer by an earlier
message, causing an uninitialized memory read.
Use msg->front.iov_len as the receive-side decode boundary, matching
other libceph reply handlers and limiting decoding to the bytes that
were actually read from the wire.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 Version: 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 Version: 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 Version: 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 Version: 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 Version: 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 Version: 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 Version: 513a8243d67f8e8d27f2883bd2f18bc87c7ca376 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/ceph/mon_client.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "1307028f082756bf453e1889aee9983d30643a4b",
"status": "affected",
"version": "513a8243d67f8e8d27f2883bd2f18bc87c7ca376",
"versionType": "git"
},
{
"lessThan": "f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e",
"status": "affected",
"version": "513a8243d67f8e8d27f2883bd2f18bc87c7ca376",
"versionType": "git"
},
{
"lessThan": "72a35070fcefa229b1b031aa7482ad3788e18f07",
"status": "affected",
"version": "513a8243d67f8e8d27f2883bd2f18bc87c7ca376",
"versionType": "git"
},
{
"lessThan": "340e0386aa39da181015bee38f309018c335ce16",
"status": "affected",
"version": "513a8243d67f8e8d27f2883bd2f18bc87c7ca376",
"versionType": "git"
},
{
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"status": "affected",
"version": "513a8243d67f8e8d27f2883bd2f18bc87c7ca376",
"versionType": "git"
},
{
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"status": "affected",
"version": "513a8243d67f8e8d27f2883bd2f18bc87c7ca376",
"versionType": "git"
},
{
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"status": "affected",
"version": "513a8243d67f8e8d27f2883bd2f18bc87c7ca376",
"versionType": "git"
},
{
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"status": "affected",
"version": "513a8243d67f8e8d27f2883bd2f18bc87c7ca376",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/ceph/mon_client.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.16"
},
{
"lessThan": "3.16",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.148",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.101",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.265",
"versionStartIncluding": "3.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.216",
"versionStartIncluding": "3.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.183",
"versionStartIncluding": "3.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.148",
"versionStartIncluding": "3.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.101",
"versionStartIncluding": "3.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.42",
"versionStartIncluding": "3.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.6",
"versionStartIncluding": "3.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "3.16",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: bound get_version reply decode to front len\n\nhandle_get_version_reply() uses msg-\u003efront_alloc_len as the decode\nboundary for MON_GET_VERSION_REPLY. That is the size of the reused\nreply buffer, not the number of bytes actually received.\n\nA truncated reply can therefore pass ceph_decode_need() and decode the\nsecond u64 from stale tail bytes left in the buffer by an earlier\nmessage, causing an uninitialized memory read.\n\nUse msg-\u003efront.iov_len as the receive-side decode boundary, matching\nother libceph reply handlers and limiting decoding to the bytes that\nwere actually read from the wire."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.6,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - The malformed MON_GET_VERSION_REPLY arrives over the ceph messenger TCP connection to a monitor; a malicious/compromised ceph-mon or an on-path attacker on the msgr1/crc-mode session triggers the bug purely with received network data.\nAC:L - The attacker fully controls the reply\u0027s hdr.front_len and tid, so truncating the reply to 8 bytes reliably makes the handler decode past the received data every time; no race or memory-layout condition outside attacker control is involved.\nPR:N - The vulnerable decode runs on any reply the client accepts for an outstanding generic request; the attacker acts as the remote server/peer and needs no credentials or account on the victim kernel client.\nUI:N - An already-mounted CephFS/RBD client issues mon_get_version requests automatically (osdmap checks, pool-dne checks, remount/latest-map waits), so no local user action is needed once the client is connected.\nS:U - The uninitialized read and the resulting bogus epoch stay within the kernel\u0027s own libceph client state; no security authority other than the affected kernel is impacted.\nC:L - Eight bytes of uninitialized kvmalloc\u0027d heap (or stale bytes of a prior reply) are consumed as req-\u003eu.newest; the read stays inside the 32-byte allocation and is not copied to userspace, so it is a small bounded uninitialized-memory disclosure that only leaks indirectly through client behaviour.\nI:L - The attacker causes kernel state (req-\u003eu.newest, r_map_dne_bound, linger map_dne_bound) to be populated from uninitialized memory rather than the wire, corrupting osdmap-epoch bookkeeping and leading to wrong pool-does-not-exist decisions, but gives no arbitrary write.\nA:H - A zero stale value trips WARN_ON(greq-\u003eresult || !greq-\u003eu.newest) in map_check_cb()/linger_map_check_cb() (panic with panic_on_warn), while a huge garbage epoch makes ceph_monc_wait_osdmap() block until mount_timeout or indefinitely and makes check_pool_dne() abort in-flight requests with -ENOENT; all repeatable at will."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-19T16:35:33.508Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/1307028f082756bf453e1889aee9983d30643a4b"
},
{
"url": "https://git.kernel.org/stable/c/f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e"
},
{
"url": "https://git.kernel.org/stable/c/72a35070fcefa229b1b031aa7482ad3788e18f07"
},
{
"url": "https://git.kernel.org/stable/c/340e0386aa39da181015bee38f309018c335ce16"
},
{
"url": "https://git.kernel.org/stable/c/d60de8253c85a02d0e6194b0735e7a562981a04c"
},
{
"url": "https://git.kernel.org/stable/c/4e7ebfaa0d14cf50e44041bfde38070d6dbc019f"
},
{
"url": "https://git.kernel.org/stable/c/0d934c934ec746d53fc7e4f53239792647bbae63"
},
{
"url": "https://git.kernel.org/stable/c/d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0"
}
],
"title": "libceph: bound get_version reply decode to front len",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-68433",
"datePublished": "2026-08-12T00:07:20.455Z",
"dateReserved": "2026-07-30T09:28:09.393Z",
"dateUpdated": "2026-08-19T16:35:33.508Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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