CVE-2026-43025: netfilter: ctnetlink: ignore explicit helper on new expectations
Noroxi assessment
Priority: Monitor (action score 29/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: Linux Linux 0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cd, 187b6ec5229ea93cb04c4f6d3b52efc80f513d0d, 21a04c31db4057deec85fcd6cc63d720b38819c3.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cd, 187b6ec5229ea93cb04c4f6d3b52efc80f513d0d, 21a04c31db4057deec85fcd6cc63d720b38819c3 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- BDU:2026-06499
- SUSE-SU-2026:22598-1
- SUSE-SU-2026:22673-1
- SUSE-SU-2026:22674-1
- SUSE-SU-2026:22675-1
- SUSE-SU-2026:22676-1
- SUSE-SU-2026:22677-1
- SUSE-SU-2026:22678-1
- SUSE-SU-2026:22680-1
- SUSE-SU-2026:22681-1
- SUSE-SU-2026:22682-1
- SUSE-SU-2026:22683-1
- SUSE-SU-2026:22684-1
- SUSE-SU-2026:22685-1
- SUSE-SU-2026:22686-1
- SUSE-SU-2026:22687-1
- SUSE-SU-2026:22689-1
- SUSE-SU-2026:22690-1
- SUSE-SU-2026:22691-1
- SUSE-SU-2026:22692-1
- Published
- May 1, 2026
- Updated
- Nov 10, 2026
- EPSS
- 0.1% · 2th percentile
- CWE
- CWE-125
Report tools
Action score
29
Monitor
Low priority for now.
- CVSS
- 29 / 40 · 7.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.3
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel3.12 and later · before 6.1.168
- linux linux kernel6.2 and later · before 6.6.134
- linux linux kernel6.7 and later · before 6.12.81
- linux linux kernel6.13 and later · before 6.18.22
- linux linux kernel6.19 and later · before 6.19.12
- linux linux kernel7.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 3.12affected
- bd0779370588386e4a67ba5d0b176cfded8e6a53 and later · before e135f8e8212cbed12a03ab8dec77fa1247139897affected · git
- bd0779370588386e4a67ba5d0b176cfded8e6a53 and later · before 2ea0f35f235f70c133ad61fe05ba013753b978c6affected · git
- bd0779370588386e4a67ba5d0b176cfded8e6a53 and later · before 0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cdaffected · git
- bd0779370588386e4a67ba5d0b176cfded8e6a53 and later · before 187b6ec5229ea93cb04c4f6d3b52efc80f513d0daffected · git
- bd0779370588386e4a67ba5d0b176cfded8e6a53 and later · before 21a04c31db4057deec85fcd6cc63d720b38819c3affected · git
- bd0779370588386e4a67ba5d0b176cfded8e6a53 and later · before 917b61fa2042f11e2af4c428e43f08199586633aaffected · git
- before 3.12not affected · semver
- 6.1.168 and later · up to and including 6.1.*not affected · semver
- 6.6.134 and later · up to and including 6.6.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.170-1 | 6.1.170-1 |
| Debian:13 | linux | before 6.12.85-1 | 6.12.85-1 |
| Debian:14 | linux | before 6.19.12-1 | 6.19.12-1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_69 | before 18-2.1 | 18-2.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_70 | before 18-2.1 | 18-2.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_71 | before 15-2.1 | 15-2.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_72 | before 14-2.1 | 14-2.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_74 | before 10-2.1 | 10-2.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_78 | before 6-2.1 | 6-2.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_80 | before 5-2.1 | 5-2.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_82 | before 3-2.1 | 3-2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_41 | before 21-150400.2.1 | 21-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_43 | before 17-150400.2.1 | 17-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_44 | before 16-150400.2.1 | 16-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_45 | before 14-150400.2.1 | 14-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_46 | before 10-150400.2.1 | 10-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_49 | before 6-150400.2.1 | 6-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_51 | before 5-150400.2.1 | 5-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_52 | before 4-150400.2.1 | 4-150400.2.1 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_27 | before 21-150500.2.2 | 21-150500.2.2 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_28 | before 20-150500.2.2 | 20-150500.2.2 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_30 | before 15-150500.2.2 | 15-150500.2.2 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_31 | before 13-150500.2.2 | 13-150500.2.2 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_37 | before 6-150500.2.2 | 6-150500.2.2 |
+67
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2026-43023May 1, 2026 · Bluetooth: SCO: fix race conditions in sco_sock_connect()31Monitor
- ← EarlierCVE-2026-43024May 1, 2026 · netfilter: nf_tables: reject immediate NF_QUEUE verdict22Monitor
- Later →CVE-2026-43026May 1, 2026 · netfilter: ctnetlink: zero expect NAT fields when CTA_EXPECT_NAT absent22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cd | Vendor (CNA) |
| Linux Linux | 187b6ec5229ea93cb04c4f6d3b52efc80f513d0d | Vendor (CNA) |
| Linux Linux | 21a04c31db4057deec85fcd6cc63d720b38819c3 | Vendor (CNA) |
| Linux Linux | 2ea0f35f235f70c133ad61fe05ba013753b978c6 | Vendor (CNA) |
| Linux Linux | 917b61fa2042f11e2af4c428e43f08199586633a | Vendor (CNA) |
| Linux Linux | e135f8e8212cbed12a03ab8dec77fa1247139897 | Vendor (CNA) |
| debian:linux | 6.1.170-1 · Debian:12 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_10 | 14-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_11 | 13-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_12 | 13-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_13 | 11-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_14 | 9-1.2 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_16 | 8-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_17 | 7-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_18 | 6-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_21 | 3-1.1 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_8 | 20-1.2 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-MICRO-6-0_Update_9 | 20-1.2 · SUSE:Linux Micro 6.1 | Package registry (OSV) |
| suse:kernel-livepatch-SLE16-RT_Update_9 | 4-160000.1.1 · SUSE:Linux Micro 6.2 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0143 · May 4, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- Low
- Availability impact
- High
Weakness class (CWE)
CWE-125 · Out-of-bounds ReadCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (8 more)Show less
- git.kernel.org/stable/c/187b6ec5229ea93cb04c4f6d3b52efc80f513d0d
- git.kernel.org/stable/c/21a04c31db4057deec85fcd6cc63d720b38819c3
- git.kernel.org/stable/c/2ea0f35f235f70c133ad61fe05ba013753b978c6
- git.kernel.org/stable/c/917b61fa2042f11e2af4c428e43f08199586633a
- git.kernel.org/stable/c/e135f8e8212cbed12a03ab8dec77fa1247139897
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- cert-portal.siemens.com/productcert/html/ssa-082556.html
- cert-portal.siemens.com/productcert/html/ssa-457936.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.