CVE-2026-74579
netfilter: nft_payload: fix mask build for partial field offload
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_payload: fix mask build for partial field offload nft_payload_offload_mask() builds the offload match mask for a payload expression that covers only part of a header field. For a partial IPv6 address match (field_len = 16, priv_len = 1) that shift is 1 << 120, which is undefined on the 32-bit int operand. It also trims only one word, so the remaining words stay 0xffffffff (and when priv_len is a multiple of 4 the trim is skipped entirely), leaving the mask covering more bytes than the rule matches. UBSAN: shift-out-of-bounds in net/netfilter/nft_payload.c:278:20 shift exponent 120 is too large for 32-bit type 'int' ... The match is byte-granular and struct nft_data is zero-initialised, so the correct mask is simply the first priv_len bytes set to 0xff. Set those bytes directly and drop the word/shift trimming; this removes the undefined shift and no longer over-masks the trailing bytes.
INFO
Published Date :
Aug. 17, 2026, 6:19 a.m.
Last Modified :
Aug. 17, 2026, 6:19 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-74579
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel to the latest version.
- Verify the patch for nft_payload.c is applied.
- Rebuild the kernel if custom modifications were made.
- Deploy the updated kernel to affected systems.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-74579.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74579 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-74579
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-74579 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74579 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'a5d45bc0dc50f9dd83703510e9804d813a9cac32', 'lessThan': 'b19b5d2e042c294e2cc1c908dc598f9d64015396', 'versionType': 'git'}, {'status': 'affected', 'version': 'a5d45bc0dc50f9dd83703510e9804d813a9cac32', 'lessThan': 'a375d8ace807767f29f276b681b6324c74929b1d', 'versionType': 'git'}, {'status': 'affected', 'version': 'a5d45bc0dc50f9dd83703510e9804d813a9cac32', 'lessThan': '16b553c46e347bc9de9946c4960654d5884a86de', 'versionType': 'git'}, {'status': 'affected', 'version': 'a5d45bc0dc50f9dd83703510e9804d813a9cac32', 'lessThan': '630295d5bba1d0e0f494cc459452eb0a0058c545', 'versionType': 'git'}, {'status': 'affected', 'version': 'a5d45bc0dc50f9dd83703510e9804d813a9cac32', 'lessThan': '39e88f28fb32bf02bd4b525c24c842c9cff5663d', 'versionType': 'git'}, {'status': 'affected', 'version': '5c2b4b4f9fa5b765b927e361e3d310bcb5773015', 'versionType': 'git'}, {'status': 'affected', 'version': '5.9.14', 'lessThan': '5.10', 'versionType': 'semver'}], 'programFiles': ['net/netfilter/nft_payload.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.10'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.10', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.151', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.103', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.44', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.8', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/netfilter/nft_payload.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_payload: fix mask build for partial field offload nft_payload_offload_mask() builds the offload match mask for a payload expression that covers only part of a header field. For a partial IPv6 address match (field_len = 16, priv_len = 1) that shift is 1 << 120, which is undefined on the 32-bit int operand. It also trims only one word, so the remaining words stay 0xffffffff (and when priv_len is a multiple of 4 the trim is skipped entirely), leaving the mask covering more bytes than the rule matches. UBSAN: shift-out-of-bounds in net/netfilter/nft_payload.c:278:20 shift exponent 120 is too large for 32-bit type 'int' ... The match is byte-granular and struct nft_data is zero-initialised, so the correct mask is simply the first priv_len bytes set to 0xff. Set those bytes directly and drop the word/shift trimming; this removes the undefined shift and no longer over-masks the trailing bytes. Added Reference https://git.kernel.org/stable/c/16b553c46e347bc9de9946c4960654d5884a86de Added Reference https://git.kernel.org/stable/c/39e88f28fb32bf02bd4b525c24c842c9cff5663d Added Reference https://git.kernel.org/stable/c/630295d5bba1d0e0f494cc459452eb0a0058c545 Added Reference https://git.kernel.org/stable/c/a375d8ace807767f29f276b681b6324c74929b1d Added Reference https://git.kernel.org/stable/c/b19b5d2e042c294e2cc1c908dc598f9d64015396