CVE-2026-43027

HIGH EPSS 2.6%
Published May 1, 20262mo ago · Modified Jun 17, 20262w ago
7.8 CVSS 3.1
High
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Published May 1, 2026 2mo ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_helper: pass helper to expect cleanup nf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy() to remove expectations belonging to the helper being unregistered. However, it passes NULL instead of the helper pointer as the data argument, so expect_iter_me() never matches any expectation and all of them survive the cleanup. After unregister returns, nfnl_cthelper_del() frees the helper object immediately. Subsequent expectation dumps or packet-driven init_conntrack() calls then dereference the freed exp->helper, causing a use-after-free. Pass the actual helper pointer so expectations referencing it are properly destroyed before the helper object is freed. BUG: KASAN: slab-use-after-free in string+0x38f/0x430 Read of size 1 at addr ffff888003b14d20 by task poc/103 Call Trace: string+0x38f/0x430 vsnprintf+0x3cc/0x1170 seq_printf+0x17a/0x240 exp_seq_show+0x2e5/0x560 seq_read_iter+0x419/0x1280 proc_reg_read+0x1ac/0x270 vfs_read+0x179/0x930 ksys_read+0xef/0x1c0 Freed by task 103: The buggy address is located 32 bytes inside of freed 192-byte region [ffff888003b14d00, ffff888003b14dc0)

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
2.6% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 13

VendorProductVersionRange
linuxlinux_kernel*≥4.14  –  <5.10.253
linuxlinux_kernel*≥5.11  –  <5.15.203
linuxlinux_kernel*≥5.16  –  <6.1.168
linuxlinux_kernel*≥6.2  –  <6.6.134
linuxlinux_kernel*≥6.7  –  <6.12.81
linuxlinux_kernel*≥6.13  –  <6.18.22
linuxlinux_kernel*≥6.19  –  <6.19.12
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any

References 8

  • git.kernel.org https://git.kernel.org/stable/c/2c16e4d64dd91227742dfe196a3e7b0568bef65a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/2cf2737c85a2ba2b52024dafe68ffad2676f97be
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/504ba4168466c91210c45acdc332479cfd5f2da6
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5cf28d5c8dcbbe8af6d3b145babe491906d7bad1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/620f3d14c1ef51d425060a3056ad8dbae8f998a3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/90bd7e8501349db3006d21fbc09df9ffcb172965
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a242a9ae58aa46ff7dae51ce64150a93957abe65
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/dc1739eff48e34cc71d4e2f03715493fbcebd8af
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/2c16e4d64dd91227742dfe196a3e7b0568bef65a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/2cf2737c85a2ba2b52024dafe68ffad2676f97be
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/504ba4168466c91210c45acdc332479cfd5f2da6
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5cf28d5c8dcbbe8af6d3b145babe491906d7bad1
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/620f3d14c1ef51d425060a3056ad8dbae8f998a3
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/90bd7e8501349db3006d21fbc09df9ffcb172965
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a242a9ae58aa46ff7dae51ce64150a93957abe65
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/dc1739eff48e34cc71d4e2f03715493fbcebd8af
    Patch