CVE-2026-89478
What it is
In the Linux kernel, the following vulnerability has been resolved: sctp: drop a chunk if its transport was removed sctp_rcv() resolves the transport once per packet and leaves it in chunk->transport. The lookup reference, or the one sctp_add_backlog() takes if the socket is owned by userspace, keeps it around until the chunk has been processed. An authenticated ASCONF DEL-IP can remove it in the meantime. sctp_assoc_rm_peer() takes the transport out of the association and calls sctp_transport_free(), which tags it dead and drops the reference the association held. There is a window on both paths: the packet can sit on the socket backlog, and on the direct path the lookup completes before bh_lock_sock(). The DATA chunk in that packet puts the removed transport back into asoc->peer.last_data_from. Once the packet is done that reference goes away and the transport is freed by RCU, so the next delayed SACK carries the pointer into the SACK chunk and sctp_outq_select_transport() reads the freed transport's state. Drop the chunk in sctp_inq_push(), next to the existing rcvr->dead check. Both paths reach it with the association's socket lock held. The peer retransmits it.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 9.8 CRITICAL (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Record status
- Received
Attack profile CVSS 3.1 · 9.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-89478.md and follow it. Check whether this project is affected by CVE-2026-89478. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/03a9d10ecf71f54b2af8020935f2033d4a132be5
- https://git.kernel.org/stable/c/0422b092a3d43ca462932ff9f747731ca078d1d4
- https://git.kernel.org/stable/c/1035bdef1efb9b1076d1a57b81e08c637ff08ecc
- https://git.kernel.org/stable/c/3537961df2163258bddc230db0e18dc14e925ea6
- https://git.kernel.org/stable/c/3fc072e7cb4a0ff251d13cfc2d24f62489cd9386
- https://git.kernel.org/stable/c/928fd7920ba37cc5637a211b9be979083413a2fa
- https://git.kernel.org/stable/c/c6c86a5e62a4fec36692ddd64b9144b660f71f96
- https://git.kernel.org/stable/c/d7cb5ad832095dc4becfdb2a36007ffd50e49fb0