CVE-2026-74671 (GCVE-0-2026-74671)
Vulnerability from cvelistv5 – Published: 2026-08-22 15:32 – Updated: 2026-08-22 15:32
VLAI
EPSS
VEX
Title
ima: fix out-of-bounds read in xattr_verify()
Summary
In the Linux kernel, the following vulnerability has been resolved:
ima: fix out-of-bounds read in xattr_verify()
The digest-length check in xattr_verify() mixes int and size_t:
if (xattr_len - sizeof(xattr_value->type) - hash_start >=
iint->ima_hash->length)
sizeof() yields size_t, so the usual arithmetic conversions promote
the whole left-hand side to unsigned 64-bit before the subtraction
runs. For a truncated xattr this underflows instead of going negative:
a 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1)
turns "1 - 1 - 1" into SIZE_MAX, which is trivially >= ima_hash->length.
The check then passes and the following memcmp() reads
iint->ima_hash->length bytes starting past the end of the buffer
vfs_getxattr_alloc() allocated for it.
Nothing upstream clamps xattr_len back into a safe range first:
ima_get_hash_algo() only special-cases xattr_len < 2 to pick a default
algorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than
failing when no HMAC key is loaded, so a truncated security.ima value
reaches the length check as-is.
Rewrite the comparison so every operand stays a signed int and no
implicit conversion to size_t can occur.
Severity
No CVSS data available.
Assigner
References
8 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
3ea7a56067e663278470c04fd655adf809e72d4d , < d823b5f4557083d1dd92096f796a78a2b1b06d10
(git)
Affected: 3ea7a56067e663278470c04fd655adf809e72d4d , < caeb105c15ea2431fa8da7ecfa242d0c68272426 (git) Affected: 3ea7a56067e663278470c04fd655adf809e72d4d , < a784b4732ac7e51862b9b210c2d8b2ab9e83568c (git) Affected: 3ea7a56067e663278470c04fd655adf809e72d4d , < b6cb134707a2127d90a58d69dd818679cae8033c (git) Affected: 3ea7a56067e663278470c04fd655adf809e72d4d , < 7e515b6c9aab452a4f0734bd7208e4e780e164ca (git) Affected: 3ea7a56067e663278470c04fd655adf809e72d4d , < 27f3924061592d0ef6b04e16f48754b6cb6adf27 (git) Affected: 3ea7a56067e663278470c04fd655adf809e72d4d , < dd04114af0d451091f7b8cbd26d9e37d011e9131 (git) Affected: 3ea7a56067e663278470c04fd655adf809e72d4d , < 5ff232d31106f45ac87c3b64e1d35a0667777797 (git) |
guessed | |
| Linux | Linux |
Affected:
3.13
Unaffected: 0 , < 3.13 (semver) Unaffected: 5.10.265 , ≤ 5.10.* (semver) Unaffected: 5.15.216 , ≤ 5.15.* (semver) Unaffected: 6.1.183 , ≤ 6.1.* (semver) Unaffected: 6.6.152 , ≤ 6.6.* (semver) Unaffected: 6.12.104 , ≤ 6.12.* (semver) Unaffected: 6.18.45 , ≤ 6.18.* (semver) Unaffected: 7.1.9 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
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"affected": [
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"product": "Linux",
"programFiles": [
"security/integrity/ima/ima_appraise.c"
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"vendor": "Linux",
"versions": [
{
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"version": "3.13"
},
{
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"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": "6.6.152",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.104",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.45",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.9",
"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": "3.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.216",
"versionStartIncluding": "3.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.183",
"versionStartIncluding": "3.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.152",
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"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.104",
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"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.45",
"versionStartIncluding": "3.13",
"vulnerable": true
},
{
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"versionEndExcluding": "7.1.9",
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{
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}
],
"negate": false,
"operator": "OR"
}
]
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],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nima: fix out-of-bounds read in xattr_verify()\n\nThe digest-length check in xattr_verify() mixes int and size_t:\n\n\tif (xattr_len - sizeof(xattr_value-\u003etype) - hash_start \u003e=\n\t\t\tiint-\u003eima_hash-\u003elength)\n\nsizeof() yields size_t, so the usual arithmetic conversions promote\nthe whole left-hand side to unsigned 64-bit before the subtraction\nruns. For a truncated xattr this underflows instead of going negative:\na 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1)\nturns \"1 - 1 - 1\" into SIZE_MAX, which is trivially \u003e= ima_hash-\u003elength.\nThe check then passes and the following memcmp() reads\niint-\u003eima_hash-\u003elength bytes starting past the end of the buffer\nvfs_getxattr_alloc() allocated for it.\n\nNothing upstream clamps xattr_len back into a safe range first:\nima_get_hash_algo() only special-cases xattr_len \u003c 2 to pick a default\nalgorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than\nfailing when no HMAC key is loaded, so a truncated security.ima value\nreaches the length check as-is.\n\nRewrite the comparison so every operand stays a signed int and no\nimplicit conversion to size_t can occur."
}
],
"providerMetadata": {
"dateUpdated": "2026-08-22T15:32:41.480Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/d823b5f4557083d1dd92096f796a78a2b1b06d10"
},
{
"url": "https://git.kernel.org/stable/c/caeb105c15ea2431fa8da7ecfa242d0c68272426"
},
{
"url": "https://git.kernel.org/stable/c/a784b4732ac7e51862b9b210c2d8b2ab9e83568c"
},
{
"url": "https://git.kernel.org/stable/c/b6cb134707a2127d90a58d69dd818679cae8033c"
},
{
"url": "https://git.kernel.org/stable/c/7e515b6c9aab452a4f0734bd7208e4e780e164ca"
},
{
"url": "https://git.kernel.org/stable/c/27f3924061592d0ef6b04e16f48754b6cb6adf27"
},
{
"url": "https://git.kernel.org/stable/c/dd04114af0d451091f7b8cbd26d9e37d011e9131"
},
{
"url": "https://git.kernel.org/stable/c/5ff232d31106f45ac87c3b64e1d35a0667777797"
}
],
"title": "ima: fix out-of-bounds read in xattr_verify()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74671",
"datePublished": "2026-08-22T15:32:41.480Z",
"dateReserved": "2026-08-15T05:44:03.925Z",
"dateUpdated": "2026-08-22T15:32:41.480Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-74671",
"date": "2026-08-29",
"epss": "0.00177",
"percentile": "0.07278"
},
"microsoft_vex": {
"current_release_date": "2026-08-24T14:50:16.000Z",
"cve": "CVE-2026-74671",
"id": "msrc_CVE-2026-74671",
"initial_release_date": "2026-08-24T01:07:20.000Z",
"product_status:known_affected": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "ima: fix out-of-bounds read in xattr_verify()",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74671.json",
"version": "2"
},
"nvd": "{\"cve\":{\"id\":\"CVE-2026-74671\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-22T16:16:41.063\",\"lastModified\":\"2026-08-22T16:16:41.063\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nima: fix out-of-bounds read in xattr_verify()\\n\\nThe digest-length check in xattr_verify() mixes int and size_t:\\n\\n\\tif (xattr_len - sizeof(xattr_value-\u003etype) - hash_start \u003e=\\n\\t\\t\\tiint-\u003eima_hash-\u003elength)\\n\\nsizeof() yields size_t, so the usual arithmetic conversions promote\\nthe whole left-hand side to unsigned 64-bit before the subtraction\\nruns. For a truncated xattr this underflows instead of going negative:\\na 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1)\\nturns \\\"1 - 1 - 1\\\" into SIZE_MAX, which is trivially \u003e= ima_hash-\u003elength.\\nThe check then passes and the following memcmp() reads\\niint-\u003eima_hash-\u003elength bytes starting past the end of the buffer\\nvfs_getxattr_alloc() allocated for it.\\n\\nNothing upstream clamps xattr_len back into a safe range first:\\nima_get_hash_algo() only special-cases xattr_len \u003c 2 to pick a default\\nalgorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than\\nfailing when no HMAC key is loaded, so a truncated security.ima value\\nreaches the length check as-is.\\n\\nRewrite the comparison so every operand stays a signed int and no\\nimplicit conversion to size_t can occur.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"security/integrity/ima/ima_appraise.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3ea7a56067e663278470c04fd655adf809e72d4d\",\"lessThan\":\"d823b5f4557083d1dd92096f796a78a2b1b06d10\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3ea7a56067e663278470c04fd655adf809e72d4d\",\"lessThan\":\"caeb105c15ea2431fa8da7ecfa242d0c68272426\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3ea7a56067e663278470c04fd655adf809e72d4d\",\"lessThan\":\"a784b4732ac7e51862b9b210c2d8b2ab9e83568c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3ea7a56067e663278470c04fd655adf809e72d4d\",\"lessThan\":\"b6cb134707a2127d90a58d69dd818679cae8033c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3ea7a56067e663278470c04fd655adf809e72d4d\",\"lessThan\":\"7e515b6c9aab452a4f0734bd7208e4e780e164ca\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3ea7a56067e663278470c04fd655adf809e72d4d\",\"lessThan\":\"27f3924061592d0ef6b04e16f48754b6cb6adf27\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3ea7a56067e663278470c04fd655adf809e72d4d\",\"lessThan\":\"dd04114af0d451091f7b8cbd26d9e37d011e9131\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3ea7a56067e663278470c04fd655adf809e72d4d\",\"lessThan\":\"5ff232d31106f45ac87c3b64e1d35a0667777797\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"security/integrity/ima/ima_appraise.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.13\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.13\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.265\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.216\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.183\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.152\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.104\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.45\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.9\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/27f3924061592d0ef6b04e16f48754b6cb6adf27\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/5ff232d31106f45ac87c3b64e1d35a0667777797\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7e515b6c9aab452a4f0734bd7208e4e780e164ca\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a784b4732ac7e51862b9b210c2d8b2ab9e83568c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b6cb134707a2127d90a58d69dd818679cae8033c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/caeb105c15ea2431fa8da7ecfa242d0c68272426\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d823b5f4557083d1dd92096f796a78a2b1b06d10\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/dd04114af0d451091f7b8cbd26d9e37d011e9131\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
"redhat_vex": {
"aggregate_severity": "Moderate",
"current_release_date": "2026-08-24T11:54:24+00:00",
"cve": "CVE-2026-74671",
"id": "CVE-2026-74671",
"initial_release_date": "2026-08-22T00:00:00+00:00",
"product_status:known_affected": "232",
"product_status:known_not_affected": "42",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: ima: fix out-of-bounds read in xattr_verify()",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74671.json",
"version": "3"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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