CVE-2025-23142 — sctp: detect and prevent references to a freed transport in sendmsg
In the Linux kernel, the following vulnerability has been resolved: sctp: detect and prevent references to a freed transport in sendmsg sctp_sendmsg() re-uses associations and transports when possible by doing a lookup based on the socket endpoint and the message destination address, and then sctp_sendmsg_to_asoc() sets the selected transport in all the message chunks to be sent. There's a possible race condition if another thread triggers the removal of that selected transport, for instance, by explicitly unbinding an address with setsockopt(SCTP_SOCKOPT_BINDX_REM), after the chunks have been set up and before the message is sent. This can happen if the send buffer is full, during the period when the sender thread temporarily releases the socket lock in sctp_wait_for_sndbuf(). This causes the access to the transport data in sctp_outq_select_transport(), when the association outqueue is flushed, to result in a use-after-free read. This change avoids this scenario by having sctp_transport_free() signal the freeing of the transport, tagging it as "dead". In order to do this, the patch restores the "dead" bit in struct sctp_transport, which was removed in commit 47faa1e4c50e ("sctp: remove the dead field of sctp_transport"). Then, in the scenario where the sender thread has released the socket lock in sctp_wait_for_sndbuf(), the bit is checked again after re-acquiring the socket lock to detect the deletion. This is done while holding a reference to the transport to prevent it from being freed in the process. If the transport was deleted while the socket lock was relinquished, sctp_sendmsg_to_asoc() will return -EAGAIN to let userspace retry the send. The bug was found by a private syzbot instance (see the error report [1] and the C reproducer that triggers it [2]).
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 11.0 | Vulnerable | NIST National Vulnerability Database |
| Linux | Linux |
version e044554e97e812eb257d073bcc130e0ea653858f≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < c6fefcb71d246baaf3bacdad1af7ff50ebcfe652≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < 9e7c37fadb3be1fc33073fcf10aa96d166caa697≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < 5bc83bdf5f5b8010d1ca5a4555537e62413ab4e2≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < 2e5068b7e0ae0a54f6cfd03a2f80977da657f1ee≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < f1a69a940de58b16e8249dff26f74c8cc59b32beversion 26e51e5287eed4d96ea66a3da95429f42940f013version 8b97e045bd6d37f96f161e4d371ae174148e1587 and 12 more≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < 7a63f4fb0efb4e69efd990cbb740a848679ec4b0version 8376fdc999be008f0e9918db52f1ed8c08f5a1c9version cd947138e8c31e8cfcd489c12e9b97271beb6e79≥ 3.18.128 and < 3.19≥ 4.4.166 and < 4.5≥ 4.9.142 and < 4.10≥ 4.14.85 and < 4.15≥ 4.19.6 and < 4.20version 4.20≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < 0f7df4899299ce4662e5f95badb9dbc57cc37fa5≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < 3257386be6a7eb8a8bfc9cbfb746df4eb4fc70e8≥ df132eff463873e14e019a07f387b4d577d6d1f9 and < 547762250220325d350d0917a7231480e0f4142b |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 6.15-rc1≥ 6.14 and < 6.14.3≥ 6.13 and < 6.13.12≥ 6.7 and < 6.12.24≥ 6.2 and < 6.6.88≥ 5.16 and < 6.1.135≥ 5.11 and < 5.15.181≥ 5.5 and < 5.10.237 and 5 more≥ 4.19.6 and < 5.4.293≥ 4.14.85 and < 4.15≥ 4.9.142 and < 4.10≥ 4.4.166 and < 4.5≥ 3.18.128 and < 3.19 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · linux/linux kernel, debian/debian linux
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 15, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
13 on the record
- git.kernel.org/stable/c/7a63f4fb0efb4e69efd990cbb740a848679ec4b0
- git.kernel.org/stable/c/0f7df4899299ce4662e5f95badb9dbc57cc37fa5
- git.kernel.org/stable/c/3257386be6a7eb8a8bfc9cbfb746df4eb4fc70e8
- git.kernel.org/stable/c/f1a69a940de58b16e8249dff26f74c8cc59b32be
- git.kernel.org/stable/c/547762250220325d350d0917a7231480e0f4142b
- git.kernel.org/stable/c/2e5068b7e0ae0a54f6cfd03a2f80977da657f1ee
- git.kernel.org/stable/c/c6fefcb71d246baaf3bacdad1af7ff50ebcfe652
- git.kernel.org/stable/c/5bc83bdf5f5b8010d1ca5a4555537e62413ab4e2
- git.kernel.org/stable/c/9e7c37fadb3be1fc33073fcf10aa96d166caa697
- lists.debian.org/debian-lts-announce/2025/05/msg00045.html
- lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- nvd.nist.gov/vuln/detail/CVE-2025-23142
- github.com/advisories/GHSA-q7q7-437c-qxh7
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 13h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 13h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-23142 is "sctp: detect and prevent references to a freed transport in sendmsg", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.23% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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