# CVE-2024-26800: tls: fix use-after-free on failed backlog decryption

> A use-after-free in the Linux kernel TLS subsystem allows attackers to cause denial of service or potentially execute code via failed backlog decryption.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 4 Apr 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-71927, DEBIAN-CVE-2024-26800, GHSA-q4hp-86wf-hj44, UBUNTU-CVE-2024-26800

## What is CVE-2024-26800?

CVE-2024-26800 is a critical use after free vulnerability in Linux kernel, published on 4 Apr 2024. 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:

tls: fix use-after-free on failed backlog decryption

When the decrypt request goes to the backlog and crypto_aead_decrypt
returns -EBUSY, tls_do_decryption will wait until all async
decryptions have completed. If one of them fails, tls_do_decryption
will return -EBADMSG and tls_decrypt_sg jumps to the error path,
releasing all the pages. But the pages have been passed to the async
callback, and have already been released by tls_decrypt_done.

The only true async case is when crypto_aead_decrypt returns
 -EINPROGRESS. With -EBUSY, we already waited so we can tell
tls_sw_recvmsg that the data is available for immediate copy, but we
need to notify tls_decrypt_sg (via the new ->async_done flag) that the
memory has already been released.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-26800?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-26800?

Apply the vendor's patch.

## Is CVE-2024-26800 being exploited?

There is no known exploitation of CVE-2024-26800 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-2024-26800 and fix it if it is affected.

What it is: CVE-2024-26800 is a critical use after free vulnerability in Linux kernel, published on 4 Apr 2024. 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-2024-26800 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-2024-26800/ (Markdown: https://insights.sbomify.com/CVE-2024-26800/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-26800
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-26800
- OSV: https://osv.dev/vulnerability/CVE-2024-26800

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-26800/
Summaries are generated and may contain mistakes; the official description above is the record.