FKIE_CVE-2026-74492
Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-19 17:21
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: do not update comments from kernel-side hash adds
mtype_resize() copies comment pointers with memcpy(), not the comment
objects themselves. During the window after an entry has been copied but
before the table swap and backlog replay, the old table is still
published for packet-side updates while the replacement-table entry
already holds the same ip_set_comment_rcu pointer.
If xt_SET --add-set ... --exist hits that old entry in this window,
mtype_add() calls ip_set_init_comment() even though packet-side adds
carry no comment payload. That call frees the shared comment through the
old entry, so the replacement-table entry now holds a stale pointer.
When the queued add is replayed on the new table, mtype_add() calls
ip_set_init_comment() again and strlen() dereferences the stale pointer.
Fix this in mtype_add() by skipping ip_set_init_comment() when
ext->target marks a packet-side add. Userspace adds still update
comments, while packet-side adds can no longer free comment storage
shared with a resize copy.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/netfilter/ipset/ip_set_hash_gen.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "6f13f4d52d06986c18f12e8bffaab944dd27ceab",
"status": "affected",
"version": "f66ee0410b1c3481ee75e5db9b34547b4d582465",
"versionType": "git"
},
{
"lessThan": "f9d6cabff1fca010562dcdb0d22b296bdca3ba5a",
"status": "affected",
"version": "f66ee0410b1c3481ee75e5db9b34547b4d582465",
"versionType": "git"
},
{
"lessThan": "16bfa7be2d76ca1e0aacfa363482e1bf8ab5042a",
"status": "affected",
"version": "f66ee0410b1c3481ee75e5db9b34547b4d582465",
"versionType": "git"
},
{
"lessThan": "661ff9c0cfbe07f8eed920dde9f7781491738207",
"status": "affected",
"version": "f66ee0410b1c3481ee75e5db9b34547b4d582465",
"versionType": "git"
},
{
"lessThan": "c710e9bf38e4e71a8db85d26a0f70c0674664207",
"status": "affected",
"version": "f66ee0410b1c3481ee75e5db9b34547b4d582465",
"versionType": "git"
},
{
"lessThan": "4ae701848e4ba9e9713375fb7d82218cbd309da2",
"status": "affected",
"version": "f66ee0410b1c3481ee75e5db9b34547b4d582465",
"versionType": "git"
},
{
"lessThan": "77dbb248a5cc7a5270cd37bbb0b635bf059a872a",
"status": "affected",
"version": "f66ee0410b1c3481ee75e5db9b34547b4d582465",
"versionType": "git"
},
{
"lessThan": "f30415929be8aeb002d557c8d3f7ab2d2188003a",
"status": "affected",
"version": "f66ee0410b1c3481ee75e5db9b34547b4d582465",
"versionType": "git"
},
{
"status": "affected",
"version": "5dd9488ae41070b69d2f4acb580f77db5705f9ca",
"versionType": "git"
},
{
"status": "affected",
"version": "a469bab3386aebff33c59506f3a95e35b91118fd",
"versionType": "git"
},
{
"lessThan": "5.5",
"status": "affected",
"version": "5.4.24",
"versionType": "semver"
},
{
"lessThan": "5.6",
"status": "affected",
"version": "5.5.8",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/netfilter/ipset/ip_set_hash_gen.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.6"
},
{
"lessThan": "5.6",
"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": "6.6.151",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ipset: do not update comments from kernel-side hash adds\n\nmtype_resize() copies comment pointers with memcpy(), not the comment\nobjects themselves. During the window after an entry has been copied but\nbefore the table swap and backlog replay, the old table is still\npublished for packet-side updates while the replacement-table entry\nalready holds the same ip_set_comment_rcu pointer.\n\nIf xt_SET --add-set ... --exist hits that old entry in this window,\nmtype_add() calls ip_set_init_comment() even though packet-side adds\ncarry no comment payload. That call frees the shared comment through the\nold entry, so the replacement-table entry now holds a stale pointer.\nWhen the queued add is replayed on the new table, mtype_add() calls\nip_set_init_comment() again and strlen() dereferences the stale pointer.\n\nFix this in mtype_add() by skipping ip_set_init_comment() when\next-\u003etarget marks a packet-side add. Userspace adds still update\ncomments, while packet-side adds can no longer free comment storage\nshared with a resize copy."
}
],
"id": "CVE-2026-74492",
"lastModified": "2026-08-19T17:21:06.203",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 8.4,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.5,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-15T13:17:54.120",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/16bfa7be2d76ca1e0aacfa363482e1bf8ab5042a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4ae701848e4ba9e9713375fb7d82218cbd309da2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/661ff9c0cfbe07f8eed920dde9f7781491738207"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6f13f4d52d06986c18f12e8bffaab944dd27ceab"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/77dbb248a5cc7a5270cd37bbb0b635bf059a872a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c710e9bf38e4e71a8db85d26a0f70c0674664207"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f30415929be8aeb002d557c8d3f7ab2d2188003a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f9d6cabff1fca010562dcdb0d22b296bdca3ba5a"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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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