# CVE-2026-52974: net: tls: fix strparser anchor skb leak on offload RX setup failure

> A memory leak in the Linux kernel TLS offload error path allows attackers to cause denial of service by exhausting kernel memory.

- **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:** 24 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-52974, DEBIAN-CVE-2026-52974, GHSA-5jx6-m427-9p5p, ROOT-OS-DEBIAN-12-CVE-2026-52974, ROOT-OS-UBUNTU-2404-CVE-2026-52974, UBUNTU-CVE-2026-52974

## What is CVE-2026-52974?

CVE-2026-52974 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 Jun 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:

net: tls: fix strparser anchor skb leak on offload RX setup failure

When tls_set_device_offload_rx() fails at tls_dev_add(), the error path
calls tls_sw_free_resources_rx() to clean up the SW context that was
initialized by tls_set_sw_offload(). This function calls
tls_sw_release_resources_rx() (which stops the strparser via
tls_strp_stop()) and tls_sw_free_ctx_rx() (which kfrees the context),
but never frees the anchor skb that was allocated by alloc_skb(0) in
tls_strp_init().

Note that tls_sw_free_resources_rx() is exclusively used for this
"failed to start offload" code path, there's no other caller.

The leak did not exist before commit 84c61fe1a75b ("tls: rx: do not use
the standard strparser"), because the standard strparser doesn't try
to pre-allocate an skb.

The normal close path in tls_sk_proto_close() handles cleanup by calling
tls_sw_strparser_done() (which calls tls_strp_done()) after dropping
the socket lock, because tls_strp_done() does cancel_work_sync() and
the strparser work handler takes the socket lock.

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

## Which versions are affected by CVE-2026-52974?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-52974?

Apply the vendor's patch.

## Is CVE-2026-52974 being exploited?

There is no known exploitation of CVE-2026-52974 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-2026-52974 and fix it if it is affected.

What it is: CVE-2026-52974 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 Jun 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-2026-52974 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-2026-52974/ (Markdown: https://insights.sbomify.com/CVE-2026-52974/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52974
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52974
- OSV: https://osv.dev/vulnerability/CVE-2026-52974

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-52974/
Summaries are generated and may contain mistakes; the official description above is the record.