# CVE-2026-23414: tls: Purge async_hold in tls_decrypt_async_wait()

> A memory leak in the Linux kernel TLS subsystem allows attackers to cause denial of service by exhausting kernel memory through specific decryption failures.

- **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:** 2 Apr 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-84056, BELL-CVE-2026-23414, DEBIAN-CVE-2026-23414, GHSA-8fgp-q3pf-q3rh, ROOT-OS-DEBIAN-12-CVE-2026-23414, ROOT-OS-DEBIAN-13-CVE-2026-23414, ROOT-OS-UBUNTU-2404-CVE-2026-23414, UBUNTU-CVE-2026-23414

## What is CVE-2026-23414?

CVE-2026-23414 is a high-severity denial of service vulnerability in Linux kernel, published on 2 Apr 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:

tls: Purge async_hold in tls_decrypt_async_wait()

The async_hold queue pins encrypted input skbs while
the AEAD engine references their scatterlist data. Once
tls_decrypt_async_wait() returns, every AEAD operation
has completed and the engine no longer references those
skbs, so they can be freed unconditionally.

A subsequent patch adds batch async decryption to
tls_sw_read_sock(), introducing a new call site that
must drain pending AEAD operations and release held
skbs. Move __skb_queue_purge(&ctx->async_hold) into
tls_decrypt_async_wait() so the purge is centralized
and every caller -- recvmsg's drain path, the -EBUSY
fallback in tls_do_decryption(), and the new read_sock
batch path -- releases held skbs on synchronization
without each site managing the purge independently.

This fixes a leak when tls_strp_msg_hold() fails part-way through,
after having added some cloned skbs to the async_hold
queue. tls_decrypt_sg() will then call tls_decrypt_async_wait() to
process all pending decrypts, and drop back to synchronous mode, but
tls_sw_recvmsg() only flushes the async_hold queue when one record has
been processed in "fully-async" mode, which may not be the case here.

[pabeni@redhat.com: added leak comment]

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-23414?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23414?

Apply the vendor's patch.

## Is CVE-2026-23414 being exploited?

There is no known exploitation of CVE-2026-23414 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-2026-23414 and fix it if it is affected.

What it is: CVE-2026-23414 is a high-severity denial of service vulnerability in Linux kernel, published on 2 Apr 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-2026-23414 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-2026-23414/ (Markdown: https://insights.sbomify.com/CVE-2026-23414/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23414
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23414
- OSV: https://osv.dev/vulnerability/CVE-2026-23414

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23414/
Summaries are generated and may contain mistakes; the official description above is the record.