CVE-2026-68315

What the bug is

When processing a RESET_IN_REQUEST from a peer, sctp_process_strreset_inreq() derives the stream count from the parameter length but does not check whether the resulting RESET_OUT_REQUEST would exceed SCTP_MAX_CHUNK_LEN. The OUT request header (sctp_strreset_outreq, 16 bytes) is 8 bytes larger than the IN request header (sctp_strreset_inreq, 8 bytes). Generally, the IP payload is bounded to 65535 bytes, so the stream list cannot be large enough to trigger the overflow. However, on interfaces with MTU > 65535 (e.g., loopback with IPv6 jumbograms), a stream list that fits within the incoming IN parameter can cause a __u16 overflow in sctp_make_strreset_req() when computing the OUT request size, leading to an undersized skb allocation and a kernel BUG: net/core/skbuff.c:207 skb_panic net/core/skbuff.c:2625 skb_put net/sctp/sm_make_chunk.c:1535 sctp_addto_chunk net/sctp/sm_make_chunk.c:3695 sctp_make_strreset_req net/sctp/stream.c:655 sctp_process_strreset_inreq The local setsockopt path validates the generated reset request size. However, for an incoming-only reset, it accounts for the smaller IN request even though the peer must generate an OUT request with the same stream list. Such a request cannot be completed successfully by the peer. Reject peer IN requests whose corresponding OUT request would exceed SCTP_MAX_CHUNK_LEN. Also tighten the local check so it does not send an IN request that would require an oversized OUT request from the peer.

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/stream.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 sctp

Prints 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

2026-08-10 (2 months ago)source

CVSS

7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsource recompute it

Attack vector

network (AV:N)source

EPSS

0.51%, higher than 42.4% 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
4.11	5.10.265	61327d8e7cfb
4.11	5.15.216	7cf7439948e3
4.11	6.1.183	60c47dea5d32
4.11	6.6.148	b255d8cd6cc6
4.11	6.12.101	6f0e39d180cd
4.11	6.18.42	1a10fe1aa9c0
4.11	7.1.6	00ae679cb21a
4.11	7.2	18ae07691d43

Debian advisories