CVE-2026-98490
In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: conntrack: fix helper UAF due to extensions realloc
While calling the helpers, a raw pointer to the extensions area is wired into expectations list:
In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation.
Make sure that helpers are called at the end after all the other extensions are already added.
Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure.
Read full descriptionShow less
And there are no atomicity guarantees provided by the API anyway.
Technical details traces, logs and code from the original report
-> nf_ct_helper()
-> helper->help()
-> nf_ct_expect_related_report()
-> nf_ct_expect_insert()
-> hlist_add_head_rcu(&exp->lnode, &master_help->expectations)CVSS
NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days
- 0.20 %
- Percentile among all scored CVEs
- 9
- Score date
- 10/20/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.
References
Show 4 references
Raw JSON (NVD)
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{
"id": "CVE-2026-98490",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "cae3a2627520c3795b54533c5328b77af3405dbe",
"lessThan": "afcf362625190c5260530b1d6c7daa98831f6b83",
"versionType": "git"
},
{
"status": "affected",
"version": "cae3a2627520c3795b54533c5328b77af3405dbe",
"lessThan": "5f23080a625dd7855ab91485c8d691a54a1979f0",
"versionType": "git"
},
{
"status": "affected",
"version": "cae3a2627520c3795b54533c5328b77af3405dbe",
"lessThan": "e02a83bb0b7a203f6a22f55ad5f426765560f811",
"versionType": "git"
},
{
"status": "affected",
"version": "cae3a2627520c3795b54533c5328b77af3405dbe",
"lessThan": "1a4151e6be57b098b7a5ebfbde58585e83200cdc",
"versionType": "git"
}
],
"programFiles": [
"net/openvswitch/conntrack.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/openvswitch/conntrack.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:16:59.903",
"references": [
{
"url": "https://git.kernel.org/stable/c/1a4151e6be57b098b7a5ebfbde58585e83200cdc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5f23080a625dd7855ab91485c8d691a54a1979f0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/afcf362625190c5260530b1d6c7daa98831f6b83",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e02a83bb0b7a203f6a22f55ad5f426765560f811",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: conntrack: fix helper UAF due to extensions realloc\n\nWhile calling the helpers, a raw pointer to the extensions area is\nwired into expectations list:\n\n -> nf_ct_helper()\n -> helper->help()\n -> nf_ct_expect_related_report()\n -> nf_ct_expect_insert()\n -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations)\n\nIn case the connection is not confirmed yet, more extensions can be\nadded afterwards with *_ext_add() calls reallocating the extension\nspace and leaving the now invalid pointer in the expectations list\nthat is later accessed while removing the expectation.\n\nMake sure that helpers are called at the end after all the other\nextensions are already added.\n\nNote that the helper rejection now leaves the mark and labels set,\nbut that's not different from how the NAT was handled before or how\nthe mark and the labels were handled on confirmation failure. And\nthere are no atomicity guarantees provided by the API anyway."
}
],
"lastModified": "2026-10-19T10:19:00.880",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}