# CVE-2026-43500: rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present

> A flaw in the Linux kernel's rxrpc module allows memory corruption when processing packets with shared fragments, potentially enabling code execution or privilege escalation.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 11 May 2026
- **Updated:** 1 Sep 2026
- **Also known as:** AZL-86366, BELL-CVE-2026-43500, DEBIAN-CVE-2026-43500, GHSA-8p2w-g92w-f4x3, UBUNTU-CVE-2026-43500

## What is CVE-2026-43500?

CVE-2026-43500 is a high-severity memory corruption vulnerability in Linux kernel, published on 11 May 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:

rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present

The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE
handler in rxrpc_verify_response() copy the skb to a linear one before
calling into the security ops only when skb_cloned() is true.  An skb
that is not cloned but still carries externally-owned paged fragments
(e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via
__ip_append_data, or a chained skb_has_frag_list()) falls through to
the in-place decryption path, which binds the frag pages directly into
the AEAD/skcipher SGL via skb_to_sgvec().

Extend the gate to also unshare when skb_has_frag_list() or
skb_has_shared_frag() is true.  This catches the splice-loopback vector
and other externally-shared frag sources while preserving the
zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC
page_pool RX, GRO).  The OOM/trace handling already in place is reused.

Weakness: CWE-123 (Write-what-where Condition), CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-43500?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43500?

Apply the vendor's patch.

## Is CVE-2026-43500 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43500 exists.

Public exploit code:

- CVE-2026-43500 / CVE-2026-31431 / CVE-2026-43284 golang hotfix (github_poc): https://github.com/attaattaatta/CVE-2026-43500
- rxkad Page-Cache Write via CVE-2026-43500 (metasploit)
- A bash script for mitigating  linux dirtyfrag exploit CVE-2026-43500, and fragnesia (github_poc): https://github.com/vorkampfer/dirty_frag_mitigation
- Linux Kernel - Local Privilege Escalation (exploitdb)
- Linux Kernel -  Local Privilege Escalation (exploitdb)

## 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-2026-43500 and fix it if it is affected.

What it is: CVE-2026-43500 is a high-severity memory corruption vulnerability in Linux kernel, published on 11 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43500 exists.

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-2026-43500/ (Markdown: https://insights.sbomify.com/CVE-2026-43500/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43500
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43500
- OSV: https://osv.dev/vulnerability/CVE-2026-43500

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43500/
Summaries are generated and may contain mistakes; the official description above is the record.