How to scan and detect CVE-2026-43029 using Nuclei?

CyberVault provides a ready Nuclei YAML detection template for CVE-2026-43029 impacting linux linux_kernel. Execute it via: nuclei -t cve-2026-43029.yaml -u .

Where can I find Proof of Concept (PoC) exploit code for CVE-2026-43029?

CyberVault provides an educational verification probe and PoC Python script for CVE-2026-43029 to audit exposed linux linux_kernel services.

How do I fix CVE-2026-43029 vulnerability in linux linux_kernel?

Review vendor security advisories and upgrade linux linux_kernel to the latest patched release. Restrict untrusted network boundaries and apply defensive workarounds if an immediate patch cannot be deployed.

Is there a public exploit or PoC available for CVE-2026-43029?

No weaponized public exploit has been observed in public threat feeds yet. Continuous surveillance is active.

What is the severity and CVSS score of CVE-2026-43029?

CVE-2026-43029 is evaluated as HIGH with an authentic CVSS base score of 7.5.

HIGH CVSS 7.5

Published: 2026-05-01

CVE-2026-43029

linux linux_kernel Security Advisory (CVE-2026-43029)

↗ Official NIST NVD Record

Seeking technical exploit breakdowns or verified PoC code for CVE-2026-43029?

🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-43029 impacting linux linux_kernel. Evaluated with CVSS Base Score of 7.5 (HIGH).

Original NVD Description

Source: NIST NVD

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix soft lockup in mptcp_recvmsg() syzbot reported a soft lockup in mptcp_recvmsg() [0]. When receiving data with MSG_PEEK | MSG_WAITALL flags, the skb is not removed from the sk_receive_queue. This causes sk_wait_data() to always find available data and never perform actual waiting, leading to a soft lockup. Fix this by adding a 'last' parameter to track the last peeked skb. This allows sk_wait_data() to make informed waiting decisions and prevent infinite loops when MSG_PEEK is used. [0]: watchdog: BUG: soft lockup - CPU#2 stuck for 156s! [server:1963] Modules linked in: CPU: 2 UID: 0 PID: 1963 Comm: server Not tainted 6.19.0-rc8 #61 PREEMPT(none) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:sk_wait_data+0x15/0x190 Code: 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 56 41 55 41 54 49 89 f4 55 48 89 d5 53 48 89 fb <48> 83 ec 30 65 48 8b 05 17 a4 6b 01 48 89 44 24 28 31 c0 65 48 8b RSP: 0018:ffffc90000603ca0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888102bf0800 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffc90000603d18 RDI: ffff888102bf0800 RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000000101 R10: 0000000000000000 R11: 0000000000000075 R12: ffffc90000603d18 R13: ffff888102bf0800 R14: ffff888102bf0800 R15: 0000000000000000 FS: 00007f6e38b8c4c0(0000) GS:ffff8881b877e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055aa7bff1680 CR3: 0000000105cbe000 CR4: 00000000000006f0 Call Trace: <TASK> mptcp_recvmsg+0x547/0x8c0 net/mptcp/protocol.c:2329 inet_recvmsg+0x11f/0x130 net/ipv4/af_inet.c:891 sock_recvmsg+0x94/0xc0 net/socket.c:1100 __sys_recvfrom+0xb2/0x130 net/socket.c:2256 __x64_sys_recvfrom+0x1f/0x30 net/socket.c:2267 do_syscall_64+0x59/0x2d0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e arch/x86/entry/entry_64.S:131 RIP: 0033:0x7f6e386a4a1d Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8d 05 f1 de 2c 00 41 89 ca 8b 00 85 c0 75 20 45 31 c9 45 31 c0 b8 2d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 6b f3 c3 66 0f 1f 84 00 00 00 00 00 41 56 41 RSP: 002b:00007ffc3c4bb078 EFLAGS: 00000246 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 000000000000861e RCX: 00007f6e386a4a1d RDX: 00000000000003ff RSI: 00007ffc3c4bb150 RDI: 0000000000000004 RBP: 00007ffc3c4bb570 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000103 R11: 0000000000000246 R12: 00005605dbc00be0 R13: 00007ffc3c4bb650 R14: 0000000000000000 R15: 0000000000000000 </TASK>

📊 CVSS v3.1 Metric Breakdown

Attack Vector

Network (AV:N)

Exploitable remotely across internet boundaries

Attack Complexity

Low (AC:L)

No specialized conditions required

Privileges Required

None (PR:N)

Unauthenticated execution

User Interaction

None (UI:N)

Zero human interaction required

Scope

Unchanged (S:U)

Confined to same security context

Confidentiality

None (C:N)

No data confidentiality impact

Integrity

None (I:N)

No system modification impact

Availability

High (A:H)

Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product	linux / linux_kernel
Affected Versions	*
Weakness Enumeration	CWE-667

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-43029 impacting linux linux_kernel.

⚡ Nuclei Detection Template (YAML) cve-2026-43029.yaml

id: cve-2026-43029

info:
  name: linux linux_kernel - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-43029 affecting linux linux_kernel.
    Evaluation: In the Linux kernel, the following vulnerability has been resolved:

mptcp: fix soft lockup in mptcp_recvmsg()

syzbot reported a soft lockup in mptcp...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-43029
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    cvss-score: 7.5
    cve-id: CVE-2026-43029
    cwe-id: CWE-667
  tags: cve,cve-2026-43029,linux,linux_kernel,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "linux_kernel"
        part: body

🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-43029.py

# Proof-of-Concept Exploit & Verification Probe for CVE-2026-43029
# Target: linux linux_kernel | CVSS: 7.5 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-43029 (linux linux_kernel)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against linux linux_kernel scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)

🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-43029.sh

# Recommended Remediation & Patching Commands for CVE-2026-43029
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install linux_kernel 2>/dev/null || \
sudo dnf upgrade linux_kernel 2>/dev/null || \
sudo yum update linux_kernel

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i linux_kernel 2>/dev/null || rpm -qa | grep -i linux_kernel

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
Verification: Inspect installed binary packages and package manager versions for affected component releases.
Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.

⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

🔗 Verified Technical References

Authorities

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Distributions

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Technical Analysis

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-43029 in linux linux_kernel?

Review vendor-specific security notices and update linux linux_kernel packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-43029?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-43029?

CVE-2026-43029 is classified with a CVSS 3.1 Base Score of 7.5 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot

7.5

HIGH SEVERITY

CVE ID CVE-2026-43029

Weakness CWE-667

Vendor linux

Product linux_kernel

Published 2026-05-01

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

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