CVE WatchOct 15, 2026

CVE-2026-43027

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_helper: pass helper to expect cleanup nf_connt

CVSS

7.8

High

EPSS

0.1%

KEV

—

Exploit Today

0-100

Published: May 1, 2026 · Last modified: Oct 15, 2026 · CWE-416

EPSS · 30d

0.1%EPSS · 30 days0.2%

2026-09-282026-10-25

Technical 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)

Official references

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CVE-2026-869167.8 HIG

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———A use after free issue was addressed with improved memory management. This issue is fixed in iOS 26.7 and iPadOS 26.7, iOS 27 and iPadOS 27, macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7.2. An app may be able to execute arbitrary code with kernel privileges.2h CVE-2026-1126558.8 HIG

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———A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 27.2, iOS 26.7.2 and iPadOS 26.7.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, tvOS 27.2, visionOS 27.2, watchOS 27.2. Processing maliciously crafted web content may lead to arbitrary code execution.2h CVE-2026-1126518.8 HIG

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———A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 27.2, iOS 26.7.2 and iPadOS 26.7.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, visionOS 27.2. Processing maliciously crafted web content may lead to arbitrary code execution.2h CVE-2026-1126378.8 HIG

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———A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 27.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, tvOS 27.2, visionOS 27.2, watchOS 27.2. Processing maliciously crafted web content may lead to arbitrary code execution.8h CVE-2026-1126268.8 HIG

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———A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 27.2, iOS 26.7.2 and iPadOS 26.7.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, visionOS 27.2. Processing maliciously crafted web content may lead to arbitrary code execution.2h