# CVE-2026-43494: net/rds: reset op_nents when zerocopy page pin fails

> A use-after-free vulnerability in the Linux kernel RDS module allows attackers to execute arbitrary code or escalate privileges via crafted network messages.

- **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:** 21 May 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-87083, BELL-CVE-2026-43494, DEBIAN-CVE-2026-43494, GHSA-m5w6-2mrp-4227, ROOT-OS-DEBIAN-11-CVE-2026-43494, ROOT-OS-DEBIAN-12-CVE-2026-43494, ROOT-OS-DEBIAN-13-CVE-2026-43494, UBUNTU-CVE-2026-43494

## What is CVE-2026-43494?

CVE-2026-43494 is a high-severity use after free vulnerability in Linux kernel, published on 21 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:

net/rds: reset op_nents when zerocopy page pin fails

When iov_iter_get_pages2() fails in rds_message_zcopy_from_user(),
the pinned pages are released with put_page(), and
rm->data.op_mmp_znotifier is cleared.  But we fail to properly
clear rm->data.op_nents.

Later when rds_message_purge() is called from rds_sendmsg() the
cleanup loop iterates over the incorrectly non zero number of
op_nents and frees them again.

Fix this by properly resetting op_nents when it should be in
rds_message_zcopy_from_user().

Weakness: CWE-1341 (Multiple Releases of Same Resource or Handle), CWE-415 (Double Free)

## Which versions are affected by CVE-2026-43494?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43494?

Apply the vendor's patch.

## Is CVE-2026-43494 being exploited?

There is no known exploitation of CVE-2026-43494 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-43494 (github_poc): https://github.com/0xredash/CVE-2026-43494
- Proof-of-concept for CVE-2026-43494 (PinTheft): Linux LPE via RDS zerocopy refcount bug + io_uring fixed buffers → SUID page-cache overwrite. Authorized research only. (github_poc): https://github.com/jayhutajulu1/CVE-2026-43494-PinTheft-PoC
- A x86_64 ASM implementation of PinTheft (CVE-2026-43494) (github_poc): https://github.com/Koshmare-Blossom/PinTheft-asm
- https://github.com/letsr00t/CVE-2026-43494-PinTheft-PoC (github_poc): https://github.com/letsr00t/CVE-2026-43494-PinTheft-PoC
- Tracking PinTheft (CVE-2026-43494, CVE-2026-43502), the RDS zerocopy double-free privilege escalation (github_poc): https://github.com/suominen/pintheft
- A Go implementation of PinTheft (CVE-2026-43494) (github_poc): https://github.com/Kagantua/PinTheft-go

## 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-2026-43494 and fix it if it is affected.

What it is: CVE-2026-43494 is a high-severity use after free vulnerability in Linux kernel, published on 21 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-43494 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-2026-43494/ (Markdown: https://insights.sbomify.com/CVE-2026-43494/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43494
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43494
- OSV: https://osv.dev/vulnerability/CVE-2026-43494

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43494/
Summaries are generated and may contain mistakes; the official description above is the record.