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CVE-2026-74287
sctp: validate embedded address parameter length
Published 2026-08-15 (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-2026-74287 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 | fixed | 6.1.180-1 | Update the kernel and reboot. Fixed in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.100-1 | Update the kernel and reboot. Fixed in 6.12.100-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
sctp_verify_asconf() and sctp_verify_param() only validate ADD_IP, DEL_IP, and SET_PRIMARY parameters against a fixed minimum size of sizeof(struct sctp_addip_param) + sizeof(struct sctp_paramhdr). This ensures the outer parameter is large enough to contain an embedded address parameter header, but does not verify that the embedded address parameter's declared length fits within the bounds of the outer parameter. Later, sctp_process_param() and sctp_process_asconf_param() extract the embedded address parameter and pass it to af->from_addr_param(), which uses the address parameter length to parse the variable-length address payload. A malformed peer can therefore advertise an embedded address parameter length that exceeds the remaining bytes in the enclosing parameter. Validate that addr_param->p.length does not exceed the space available after the sctp_addip_param header before processing the embedded address parameter. Reject malformed parameters when the embedded address length extends beyond the enclosing parameter bounds. This prevents out-of-bounds reads when parsing malformed parameters carried in INIT or ASCONF processing paths.
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, sidm
- 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
- 2026-08-15 (2 months ago)source
- CVSS
- 9.1 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.73%, higher than 53.5% 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 | 5.10.261 | 06c8bf48505f |
| 2.6.12 | 5.15.212 | 28ba1d3c9566 |
| 2.6.12 | 6.1.178 | 3a44b2602d57 |
| 2.6.12 | 6.6.145 | 85f54cf58916 |
| 2.6.12 | 6.12.97 | 92e4adfee56f |
| 2.6.12 | 6.18.40 | ed8605c6f39b |
| 2.6.12 | 7.1.5 | 0c674b20c9cd |
| 2.6.12 | 7.2 | e9361d0ca55c |
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 bug is reached when the kernel parses SCTP INIT/INIT-ACK or ASCONF chunks from a remote peer via sctp_rcv() -> sctp_do_sm() -> sctp_process_init()/sctp_process_asconf(), so any routable attacker can deliver the malformed ADD-IP/SET_PRIMARY TLVs over the network.
- AC:LAttack complexity, low
- Exploitation is deterministic packet crafting (minimal outer TLV length with an oversized embedded address length); no race, memory-layout lottery, or victim-specific state is required beyond a target that has SCTP ADD-IP/asconf enabled, which is a normal configuration for SCTP HA/telecom servers.
- PR:NPrivileges required, none
- No local privileges or pre-existing credentials are needed; an unauthenticated remote peer can send a crafted INIT to a listening SCTP endpoint or complete a handshake and send ASCONF/INIT-ACK traffic, and the vulnerable parsing runs before any application-level authentication.
- UI:NUser interaction, none
- Exploitation requires only sending SCTP packets to a reachable endpoint; no victim must open files, click links, or perform any interactive action beyond ordinary network exposure of an SCTP service.
- S:UScope, unchanged
- Impact is confined to the kernel SCTP stack on the receiving host (out-of-bounds kernel reads and possible crash); it does not cross a VM, container, or IOMMU security boundary.
- C:HConfidentiality impact, high
- from_addr_param() performs out-of-bounds reads of up to 16 bytes (IPv6 address field) beyond the enclosing parameter boundary when the embedded length is inflated, exposing adjacent skb/kernel memory per kernel CVSS guidance that out-of-bounds reads warrant High confidentiality impact.
- I:NIntegrity impact, none
- The defect is an out-of-bounds read only; no kernel memory is written and the fix does not address any write primitive, so integrity impact is None.
- A:HAvailability impact, high
- Reading beyond the validated parameter bounds can access unmapped memory past the skb chunk and trigger a kernel fault/oops on affected builds; even when bounded within the skb, this class of SCTP parser OOB reads is treated as High availability impact because it is remotely triggerable and may panic the host.