# CVE-2023-53491: start_kernel: Add __no_stack_protector function attribute

> A missing stack protector attribute in the Linux kernel can cause a panic during early boot, leading to a denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Oct 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-75104, BELL-CVE-2023-53491, DEBIAN-CVE-2023-53491, GHSA-w4g3-pp54-phhq, ROOT-OS-DEBIAN-11-CVE-2023-53491, ROOT-OS-DEBIAN-12-CVE-2023-53491, ROOT-OS-UBUNTU-2204-CVE-2023-53491, UBUNTU-CVE-2023-53491

## What is CVE-2023-53491?

CVE-2023-53491 is a high-severity denial of service vulnerability in Linux kernel, published on 1 Oct 2025. 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:

start_kernel: Add __no_stack_protector function attribute

Back during the discussion of
commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try")
we discussed the need for a function attribute to control the omission
of stack protectors on a per-function basis; at the time Clang had
support for no_stack_protector but GCC did not. This was fixed in
gcc-11. Now that the function attribute is available, let's start using
it.

Callers of boot_init_stack_canary need to use this function attribute
unless they're compiled with -fno-stack-protector, otherwise the canary
stored in the stack slot of the caller will differ upon the call to
boot_init_stack_canary. This will lead to a call to __stack_chk_fail()
then panic.

## Which versions are affected by CVE-2023-53491?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53491?

Apply the vendor's patch.

## Is CVE-2023-53491 being exploited?

There is no known exploitation of CVE-2023-53491 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-2023-53491 and fix it if it is affected.

What it is: CVE-2023-53491 is a high-severity denial of service vulnerability in Linux kernel, published on 1 Oct 2025. 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-2023-53491 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-2023-53491/ (Markdown: https://insights.sbomify.com/CVE-2023-53491/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53491
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53491
- OSV: https://osv.dev/vulnerability/CVE-2023-53491

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53491/
Summaries are generated and may contain mistakes; the official description above is the record.