# 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.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-104454, BELL-CVE-2026-98077, DEBIAN-CVE-2026-98077, GHSA-x62x-qq6c-v89q, UBUNTU-CVE-2026-98077

## 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.

## Is CVE-2026-98077 being exploited?

There is no known exploitation of CVE-2026-98077 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98077 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-98077 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-98077/ (Markdown: https://insights.sbomify.com/CVE-2026-98077/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98077
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98077
- OSV: https://osv.dev/vulnerability/CVE-2026-98077

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98077/
Summaries are generated and may contain mistakes; the official description above is the record.