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NVD / CVE Program· CNA Linux

CVE-2026-43036: net: use skb_header_pointer() for TCPv4 GSO frag_off check

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.15% (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 362bacb37d88a178bfaefc4484623eae44425a70, 5057502630fbc8ce468ff617ff59af275960b537, cc91202fc20a44aab4c206f12a2bfe05da936051; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 362bacb37d88a178bfaefc4484623eae44425a70, 5057502630fbc8ce468ff617ff59af275960b537, cc91202fc20a44aab4c206f12a2bfe05da936051; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes 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: net: use skb_header_pointer() for TCPv4 GSO frag_off check Syzbot reported a KMSAN uninit-value warning in gso_features_check() called from netif_skb_features() [1]. gso_features_check() reads iph->frag_off to decide whether to clear mangleid_features. Accessing the IPv4 header via ip_hdr()/inner_ip_hdr() can rely on skb header offsets that are not always safe for direct dereference on packets injected from PF_PACKET paths. Use skb_header_pointer() for the TCPv4 frag_off check so the header read is robust whether data is already linear or needs copying. [1] https://syzkaller.appspot.com/bug?extid=1543a7d954d9c6d00407

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 1, 2026
Updated
Nov 6, 2026
EPSS
0.1% · 4th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 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.

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.

Follow CVE-2026-43036

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.7 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

    • 4.7affected
    • cbc53e08a793b073e79f42ca33f1f3568703540d and later · before 362bacb37d88a178bfaefc4484623eae44425a70affected · git
    • cbc53e08a793b073e79f42ca33f1f3568703540d and later · before 5057502630fbc8ce468ff617ff59af275960b537affected · git
    • cbc53e08a793b073e79f42ca33f1f3568703540d and later · before f7a6cd508e9e825a2c69fa9e13d41ee156852f25affected · git
    • cbc53e08a793b073e79f42ca33f1f3568703540d and later · before cc91202fc20a44aab4c206f12a2bfe05da936051affected · git
    • cbc53e08a793b073e79f42ca33f1f3568703540d and later · before d970341cfa5594614c7a6634886c7688b4f5cafdaffected · git
    • cbc53e08a793b073e79f42ca33f1f3568703540d and later · before ddc748a391dd8642ba6b2e4fe22e7f2ddf84b7f0affected · git
    • before 4.7not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 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.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.12-16.19.12-1
SUSE:Linux Enterprise Live Patching 12 SP5kernel-defaultbefore 4.12.14-122.320.14.12.14-122.320.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_85before 1-8.3.11-8.3.1
SUSE:Linux Enterprise Server 12 SP5-LTSSkernel-sourcebefore 4.12.14-122.320.14.12.14-122.320.1
SUSE:Linux Enterprise Server 12 SP5-LTSSkernel-symsbefore 4.12.14-122.320.14.12.14-122.320.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • 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 KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-43034May 1, 2026 · bnxt_en: set backing store type from query type
    22Monitor
  • ← EarlierCVE-2026-43035May 1, 2026 · net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak
    22Monitor
  • Later →CVE-2026-43037May 1, 2026 · ip6_tunnel: clear skb2->cb[] in ip4ip6_err()
    39Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux362bacb37d88a178bfaefc4484623eae44425a70Vendor (CNA)
Linux Linux5057502630fbc8ce468ff617ff59af275960b537Vendor (CNA)
Linux Linuxcc91202fc20a44aab4c206f12a2bfe05da936051Vendor (CNA)
Linux Linuxd970341cfa5594614c7a6634886c7688b4f5cafdVendor (CNA)
Linux Linuxddc748a391dd8642ba6b2e4fe22e7f2ddf84b7f0Vendor (CNA)
Linux Linuxf7a6cd508e9e825a2c69fa9e13d41ee156852f25Vendor (CNA)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
debian:linux6.12.85-1 · Debian:13Package registry (OSV)
suse:kernel-default4.12.14-122.320.1 · SUSE:Linux Enterprise Live Patching 12 SP5Package registry (OSV)
suse:kernel-source4.12.14-122.320.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:kernel-syms4.12.14-122.320.1 · SUSE:Linux Enterprise Server 12 SP5-LTSSPackage registry (OSV)
suse:kgraft-patch-SLE12-SP5_Update_851-8.3.1 · SUSE:Linux Enterprise Live Patching 12 SP5Package 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 researchers

Finders, 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.

  • CVE-2024-50302528 days apartHID: core: zero-initialize the report bufferKEV
    52Plan
  • CVE-2026-5298954 days apartnvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers
    39Monitor
  • CVE-2026-5322555 days apartsctp: fix uninit-value in __sctp_rcv_asconf_lookup()
    36Monitor
  • CVE-2026-5317055 days apartaccel/ethosu: reject DMA commands with uninitialized length
    35Monitor
  • CVE-2026-431395 days apartxfrm6: fix uninitialized saddr in xfrm6_get_saddr()
    34Monitor
  • CVE-2026-432917 days apartnet: nfc: nci: Fix parameter validation for packet data
    33Monitor

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.

All national notices →

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-908 · Use of Uninitialized Resource

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records