CVE-2026-98077

What the bug is

sip_skip_whitespace() returns dptr unchanged when its own loop exhausts the buffer (dptr == limit), instead of NULL like its sibling sip_follow_continuation() returns on its own "no more data" path. ct_sip_get_header() only checks for NULL after calling it: dptr = sip_skip_whitespace(dptr, limit); if (dptr == NULL) break; if (*dptr != ':' || ++dptr >= limit) break; so a recognized header name followed only by spaces/tabs running to the exact end of the SIP payload, with no colon, makes the very next statement read one byte past the buffer. Make both "no more data" outcomes return NULL, matching the convention sip_follow_continuation() already uses and that both existing callers already check for.

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/netfilter/nf_conntrack_sip.c

What this is

NETFILTERMAINTAINERS section matched on net/netfilter/ · netfilter-devel@vger.kernel.org · Maintained

Kernel module

nf_conntrack_sip

Check it on the machine

grep -wE 'CONFIG_NETFILTER|CONFIG_NF_CONNTRACK_SIP' /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 nf_conntrack_sip

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 switches

CONFIG_NETFILTER, CONFIG_NF_CONNTRACK_SIP

Reads as

all on means the file is compiled; any one off means it is not.

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

2026-09-25 (24 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.5% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

net/netfilter

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
2.6.26	5.10.271	9ae0a87e6f51
2.6.26	5.15.222	b6277622b732
2.6.26	6.1.189	0cfb96a118c5
2.6.26	6.6.158	c6beb08b1a9f
2.6.26	6.12.111	60c012b2d05e
2.6.26	6.18.53	4be8380e3af0
2.6.26	7.2.7	4a30aa2ba007
2.6.26	7.3	e8f8231824b5

Debian advisories