CVE-2026-74492
netfilter: ipset: do not update comments from kernel-side hash adds
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: do not update comments from kernel-side hash adds mtype_resize() copies comment pointers with memcpy(), not the comment objects themselves. During the window after an entry has been copied but before the table swap and backlog replay, the old table is still published for packet-side updates while the replacement-table entry already holds the same ip_set_comment_rcu pointer. If xt_SET --add-set ... --exist hits that old entry in this window, mtype_add() calls ip_set_init_comment() even though packet-side adds carry no comment payload. That call frees the shared comment through the old entry, so the replacement-table entry now holds a stale pointer. When the queued add is replayed on the new table, mtype_add() calls ip_set_init_comment() again and strlen() dereferences the stale pointer. Fix this in mtype_add() by skipping ip_set_init_comment() when ext->target marks a packet-side add. Userspace adds still update comments, while packet-side adds can no longer free comment storage shared with a resize copy.
INFO
Published Date :
Aug. 15, 2026, 1:17 p.m.
Last Modified :
Aug. 15, 2026, 1:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-74492
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
- Apply the netfilter: ipset patch to the Linux kernel.
- Update the Linux kernel to include the fix.
- Review kernel code for similar comment handling issues.
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-2026-74492.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74492 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-2026-74492
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-2026-74492 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74492 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.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 15, 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': 'f66ee0410b1c3481ee75e5db9b34547b4d582465', 'lessThan': '661ff9c0cfbe07f8eed920dde9f7781491738207', 'versionType': 'git'}, {'status': 'affected', 'version': 'f66ee0410b1c3481ee75e5db9b34547b4d582465', 'lessThan': 'c710e9bf38e4e71a8db85d26a0f70c0674664207', 'versionType': 'git'}, {'status': 'affected', 'version': 'f66ee0410b1c3481ee75e5db9b34547b4d582465', 'lessThan': '4ae701848e4ba9e9713375fb7d82218cbd309da2', 'versionType': 'git'}, {'status': 'affected', 'version': 'f66ee0410b1c3481ee75e5db9b34547b4d582465', 'lessThan': '77dbb248a5cc7a5270cd37bbb0b635bf059a872a', 'versionType': 'git'}, {'status': 'affected', 'version': 'f66ee0410b1c3481ee75e5db9b34547b4d582465', 'lessThan': 'f30415929be8aeb002d557c8d3f7ab2d2188003a', 'versionType': 'git'}, {'status': 'affected', 'version': '5dd9488ae41070b69d2f4acb580f77db5705f9ca', 'versionType': 'git'}, {'status': 'affected', 'version': 'a469bab3386aebff33c59506f3a95e35b91118fd', 'versionType': 'git'}, {'status': 'affected', 'version': '5.4.24', 'lessThan': '5.5', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.5.8', 'lessThan': '5.6', 'versionType': 'semver'}], 'programFiles': ['net/netfilter/ipset/ip_set_hash_gen.h'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.6'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.6', '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-rc6', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/netfilter/ipset/ip_set_hash_gen.h'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: do not update comments from kernel-side hash adds mtype_resize() copies comment pointers with memcpy(), not the comment objects themselves. During the window after an entry has been copied but before the table swap and backlog replay, the old table is still published for packet-side updates while the replacement-table entry already holds the same ip_set_comment_rcu pointer. If xt_SET --add-set ... --exist hits that old entry in this window, mtype_add() calls ip_set_init_comment() even though packet-side adds carry no comment payload. That call frees the shared comment through the old entry, so the replacement-table entry now holds a stale pointer. When the queued add is replayed on the new table, mtype_add() calls ip_set_init_comment() again and strlen() dereferences the stale pointer. Fix this in mtype_add() by skipping ip_set_init_comment() when ext->target marks a packet-side add. Userspace adds still update comments, while packet-side adds can no longer free comment storage shared with a resize copy. Added Reference https://git.kernel.org/stable/c/4ae701848e4ba9e9713375fb7d82218cbd309da2 Added Reference https://git.kernel.org/stable/c/661ff9c0cfbe07f8eed920dde9f7781491738207 Added Reference https://git.kernel.org/stable/c/77dbb248a5cc7a5270cd37bbb0b635bf059a872a Added Reference https://git.kernel.org/stable/c/c710e9bf38e4e71a8db85d26a0f70c0674664207 Added Reference https://git.kernel.org/stable/c/f30415929be8aeb002d557c8d3f7ab2d2188003a