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CVE-2026-80717
sctp: validate Adaptation Indication parameter length
Published 2026-08-28 (2 months ago) by the Linux kernel CNA. Subsystem net/sctp. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-80717 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixedDLA-4777-1 · 2026-09-08 · text | 6.1.187-1 | Update the kernel and reboot. DLA-4777-1 shipped the fix on 2026-09-08, in 6.1.187-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.105-1 | Update the kernel and reboot. Fixed in 6.12.105-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.8-1 | Update the kernel and reboot. Fixed in 7.1.8-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.8-1 | Update the kernel and reboot. Fixed in 7.1.8-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4788-1 · 2026-09-19 · text | 6.12.107-1~deb12u1 | Update the kernel and reboot. DLA-4788-1 shipped the fix on 2026-09-19, in 6.12.107-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
The Adaptation Layer Indication parameter contains a fixed 32-bit Adaptation Code Point after its parameter header. However, sctp_verify_param() accepts a header-only parameter because the generic parameter walker only requires the header to be present. sctp_process_param() then reads adaptation_ind beyond the declared parameter. When the malformed parameter is last in an INIT, the read starts at the receive skb tail, and the value is copied into the state cookie returned in the INIT ACK. This may disclose four receive-buffer tail bytes. Require the declared parameter length to match the fixed structure size and abort the association through the existing invalid parameter length path otherwise.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
net/sctp/sm_make_chunk.c
- What this is
- SCTP PROTOCOLMAINTAINERS section matched on net/sctp/ · linux-sctp@vger.kernel.org · Maintained
- Kernel module
- sctp
Check it on the machine
grep -w CONFIG_IP_SCTP /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w sctpPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this as a loadable module. Every release below compiles it as a module on every flavour, so whether the code is in the running kernel depends on whether that module is loaded.
- bookworm, trixie, forky, sid, bookworm · linux-6.12m
- m
- a loadable module on every flavour - check lsmod, can be blacklisted
- Build switch
- CONFIG_IP_SCTP
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-28 (2 months ago)source
- CVSS
- 7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.33%, higher than 24.5% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- net/sctp
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 2.6.12 | 5.10.265 | fa7861ddbe3b |
| 2.6.12 | 5.15.216 | 4c92c601c061 |
| 2.6.12 | 6.1.183 | 7b7e4e3640d5 |
| 2.6.12 | 6.6.151 | 93942b5772e0 |
| 2.6.12 | 6.12.103 | 5fd7cfc708df |
| 2.6.12 | 6.18.44 | 17b412468c7a |
| 2.6.12 | 7.1.8 | bfa28cf99eb4 |
| 2.6.12 | 7.2 | 74b21f52c5c5 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4788-1 | 2026-09-19 | bookworm 6.12.107-1~deb12u1 | tracker |
| DLA-4777-1 | 2026-09-08 | bookworm 6.1.187-1 | tracker |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:NAttack vector, network
- The flaw is reached when a remote peer sends a crafted SCTP INIT to a listening endpoint; packets enter sctp_rcv() and sctp_sf_do_5_1B_init(), which calls sctp_verify_init() and sctp_process_init() before any association authentication.
- AC:LAttack complexity, low
- Exploitation is deterministic SCTP packet crafting: place SCTP_PARAM_ADAPTATION_LAYER_IND last in INIT with a 4-byte header-only length so sctp_process_param() reads past the TLV into skb tail memory; no race, memory-layout lottery, or rare victim state is required beyond SCTP being enabled.
- PR:NPrivileges required, none
- INIT processing is pre-authentication SCTP handshake handling on a listening server; the attacker needs only network reachability to the SCTP port and no local account, Linux capabilities, or init-namespace privileges on the target host.
- UI:NUser interaction, none
- No victim user action such as opening files or clicking links is required; exploitation needs only that an SCTP listener is reachable and automatically processes inbound INIT chunks during normal server operation.
- S:UScope, unchanged
- Impact is a bounded kernel skb out-of-bounds read whose contents are returned to the remote peer in the INIT-ACK state cookie; it does not cross VM, container, or IOMMU security boundaries.
- C:HConfidentiality impact, high
- sctp_process_param() performs an out-of-bounds read of four kernel receive-buffer tail bytes when adaptation_ind is accessed beyond a header-only parameter; those bytes are copied into the state cookie and disclosed to the attacker in INIT-ACK.
- I:NIntegrity impact, none
- The defect is an out-of-bounds read only; no kernel memory is written, no association structures are corrupted, and the fix does not address any write primitive or control-flow hijacking.
- A:NAvailability impact, none
- The out-of-bounds read copies four skb tail bytes into the association cookie and INIT-ACK without dereferencing unmapped memory; the commit describes information disclosure only and no kernel oops, panic, or hang.