CVE-2026-46227: Linux kernel · sctp: revalidate list cursor after sctp_sendmsg_to_asoc() in SCTP_SENDALL
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in f3a3f0b406b4b7eb3cea35a23fa2bf170848b104 : patch Linux kernel soon.
Data as of 26 Oct 2026, 09:29 UTC
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in f3a3f0b406b4b7eb3cea35a23fa2bf170848b104, c9dadb31f36045a8cb65df4bd75e7237ef21a4b5, bf0f40d8107e2ce827521968dc6926f3e13728ae +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: sctp: revalidate list cursor after sctp_sendmsg_to_asoc() in SCTP_SENDALL The SCTP_SENDALL path in sctp_sendmsg() iterates ep->asocs with list_for_each_entry_safe(), which caches the next entry in @tmp before the loop body runs. The body calls sctp_sendmsg_to_asoc(), which may drop the socket lock inside sctp_wait_for_sndbuf(). While the lock is dropped, another thread can SCTP_SOCKOPT_PEELOFF the association cached in @tmp, migrating it to a new endpoint via sctp_sock_migrate() (list_del_init() + list_add_tail() to newep->asocs), and optionally close the new socket which frees the association via kfree_rcu(). The cached @tmp can also be freed by a network ABORT for that association, processed in softirq while the lock is dropped. sctp_wait_for_sndbuf() revalidates @asoc (the current entry) on re-lock via the "sk != asoc->base.sk" and "asoc->base.dead" checks, but nothing revalidates @tmp. After a successful return, the iterator advances to the stale @tmp, yielding either a use-after-free (if the peeled socket was closed) or a list-walk onto the new endpoint's list head (type confusion of &newep->asocs as a struct sctp_association *). Both are reachable from CapEff=0; the type-confusion path gives controlled indirect call via the outqueue.sched->init_sid pointer. Fix by re-deriving @tmp from @asoc after sctp_sendmsg_to_asoc() returns. @asoc is known to still be on ep->asocs at that point: the only callers that list_del an association from ep->asocs are sctp_association_free() (which sets asoc->base.dead) and sctp_assoc_migrate() (which changes asoc->base.sk), and sctp_wait_for_sndbuf() checks both under the lock before any successful return; a tripped check propagates as err < 0 and the loop bails before the re-derive. The SCTP_ABORT path in sctp_sendmsg_check_sflags() returns 0 and the loop hits 'continue' before sctp_sendmsg_to_asoc() is ever called, so the @tmp cached by list_for_each_entry_safe() still covers the lock-held free that ba59fb027307 ("sctp: walk the list of asoc safely") was added for.
References
- git.kernel.org/stable/c/f3a3f0b406b4b7eb3cea35a23fa2bf170848b104 (opens in a new tab)
- git.kernel.org/stable/c/0dbc8cde64280fc37cdd678cced34eaf96cfb197 (opens in a new tab)
- git.kernel.org/stable/c/0c7b55974f97b78d1109025eadf084e74cbf330f (opens in a new tab)
- git.kernel.org/stable/c/1bfb06ecb00f7fdf35dba8e8f2877346cbe5e078 (opens in a new tab)
- git.kernel.org/stable/c/6187a172d6ed57d6b2c327836e4407c6456e639d (opens in a new tab)
- git.kernel.org/stable/c/c9dadb31f36045a8cb65df4bd75e7237ef21a4b5 (opens in a new tab)
- git.kernel.org/stable/c/bf0f40d8107e2ce827521968dc6926f3e13728ae (opens in a new tab)
- git.kernel.org/stable/c/abb5f36771cc4c05899b34000829a787572a8817 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-46227 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2482564 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46227.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27731 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36956 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26515 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:27735 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:34094 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36018 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59143 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36349 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59146 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26535 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33899 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26563 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59142 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59147 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59145 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59148 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59149 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:36348 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26462 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)