CVE-2026-43025
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: ignore explicit helper on new expectations Use the existing master conntrack helper, anything else is not really supported and it just makes validation more complicated, so just ignore what helper userspace suggests for this expectation. This was uncovered when validating CTA_EXPECT_CLASS via different helper provided by userspace than the existing master conntrack helper: BUG: KASAN: slab-out-of-bounds in nf_ct_expect_related_report+0x2479/0x27c0 Read of size 4 at addr ffff8880043fe408 by task poc/102 Call Trace: nf_ct_expect_related_report+0x2479/0x27c0 ctnetlink_create_expect+0x22b/0x3b0 ctnetlink_new_expect+0x4bd/0x5c0 nfnetlink_rcv_msg+0x67a/0x950 netlink_rcv_skb+0x120/0x350 Allowing to read kernel memory bytes off the expectation boundary. CTA_EXPECT_HELP_NAME is still used to offer the helper name to userspace via netlink dump.
Severity
HIGH
CVSS score
7.3
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-01 15:16:46.903000
Last modified
2026-10-19 20:18:00.853000
View original CVE JSON
{
"id": "CVE-2026-43025",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-05-01T15:16:46.903",
"lastModified": "2026-10-19T20:18:00.853",
"vulnStatus": "Modified",
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"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: ignore explicit helper on new expectations\n\nUse the existing master conntrack helper, anything else is not really\nsupported and it just makes validation more complicated, so just ignore\nwhat helper userspace suggests for this expectation.\n\nThis was uncovered when validating CTA_EXPECT_CLASS via different helper\nprovided by userspace than the existing master conntrack helper:\n\n BUG: KASAN: slab-out-of-bounds in nf_ct_expect_related_report+0x2479/0x27c0\n Read of size 4 at addr ffff8880043fe408 by task poc/102\n Call Trace:\n nf_ct_expect_related_report+0x2479/0x27c0\n ctnetlink_create_expect+0x22b/0x3b0\n ctnetlink_new_expect+0x4bd/0x5c0\n nfnetlink_rcv_msg+0x67a/0x950\n netlink_rcv_skb+0x120/0x350\n\nAllowing to read kernel memory bytes off the expectation boundary.\n\nCTA_EXPECT_HELP_NAME is still used to offer the helper name to userspace\nvia netlink dump."
}
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