CVE-2026-98077 netfilter: nf_conntrack_sip: fix OOB read in sip_skip_whitespace()
A remote attacker can trigger an out-of-bounds read in the Linux kernel's SIP conntrack module, potentially causing a crash or leaking memory.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98077?
CVE-2026-98077 is a memory corruption vulnerability in Linux, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_sip: fix OOB read in sip_skip_whitespace()
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.
Which versions are affected by CVE-2026-98077?
How do I fix CVE-2026-98077?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-98077 being exploited?
There is no known exploitation of CVE-2026-98077 in the wild and no public exploit code.
Sources
Also known as AZL-104454, BELL-CVE-2026-98077, DEBIAN-CVE-2026-98077, GHSA-x62x-qq6c-v89q, UBUNTU-CVE-2026-98077.