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.
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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
No data.
No data.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 01 May 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | netfilter: ctnetlink: ignore explicit helper on new expectations | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-01T14:15:27.103Z
Reserved: 2026-05-01T14:12:55.976Z
Link: CVE-2026-43025
Vulnrichment
No data.
NVD
Status : Awaiting Analysis
Published: 2026-05-01T15:16:46.903
Modified: 2026-05-01T15:24:14.893
Link: CVE-2026-43025
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.