# CVE-2026-52915: netfilter: ip6t_hbh: reject oversized option lists

> A missing bounds check in the Linux kernel netfilter module allows an attacker to trigger an out-of-bounds array access, potentially causing a crash or code execution.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-90908, BELL-CVE-2026-52915, DEBIAN-CVE-2026-52915, GHSA-9hfh-p7qh-475c, ROOT-OS-DEBIAN-11-CVE-2026-52915, ROOT-OS-DEBIAN-12-CVE-2026-52915, ROOT-OS-UBUNTU-2204-CVE-2026-52915, ROOT-OS-UBUNTU-2404-CVE-2026-52915, UBUNTU-CVE-2026-52915

## What is CVE-2026-52915?

CVE-2026-52915 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: ip6t_hbh: reject oversized option lists

struct ip6t_opts stores at most IP6T_OPTS_OPTSNR option descriptors,
but hbh_mt6_check() does not reject larger optsnr values supplied from
userspace.

Validate optsnr in the rule setup path so only match data that fits the
fixed-size opts array can be installed. This follows the existing xtables
pattern of rejecting invalid user-provided counts in checkentry() and
keeps the packet matching path unchanged.

`struct ip6t_opts` has a fixed `opts[IP6T_OPTS_OPTSNR]` array,
where `IP6T_OPTS_OPTSNR` is 16, then off-by-one array access is possible:

[  137.924693][ T8692] UBSAN: array-index-out-of-bounds in ../net/ipv6/netfilter/ip6t_hbh.c:110:29
[  137.926167][ T8692] index 16 is out of range for type '__u16 [16]'

Weakness: CWE-129 (Improper Validation of Array Index), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-52915?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-52915?

Apply the vendor's patch.

## Is CVE-2026-52915 being exploited?

There is no known exploitation of CVE-2026-52915 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-52915 and fix it if it is affected.

What it is: CVE-2026-52915 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-52915 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-52915/ (Markdown: https://insights.sbomify.com/CVE-2026-52915/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52915
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52915
- OSV: https://osv.dev/vulnerability/CVE-2026-52915

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52915/
Summaries are generated and may contain mistakes; the official description above is the record.