# CVE-2026-53151: rxrpc: Fix the ACK parser to extract the SACK table for parsing

> A flaw in the Linux kernel's AF_RXRPC module allows attackers to cause memory corruption or denial of service via crafted fragmented UDP packets.

- **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:** 25 Jun 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-90306, BELL-CVE-2026-53151, DEBIAN-CVE-2026-53151, GHSA-fp35-jcpc-9wwg, ROOT-OS-DEBIAN-13-CVE-2026-53151, ROOT-OS-UBUNTU-2404-CVE-2026-53151, UBUNTU-CVE-2026-53151

## What is CVE-2026-53151?

CVE-2026-53151 is a critical memory corruption vulnerability in Linux kernel, published on 25 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:

rxrpc: Fix the ACK parser to extract the SACK table for parsing

Fix modification of the received skbuff in rxrpc_input_soft_acks() and a
potential incorrect access of the buffer in a fragmented UDP packet (the
packet would probably have to be deliberately pre-generated as fragmented)
when AF_RXRPC tries to extract the contents of the SACK table by copying
out the contents of the SACK table into a buffer before attempting to parse

AF_RXRPC assumes that it can just call skb_condense() and then validly
access the SACK table from skb->data and that it will be a flat buffer -
but skb_condense() can silently fail to do anything under some
circumstances.

Note that whilst rxrpc_input_soft_acks() should be able to parse extended
ACKs, the rest of AF_RXRPC doesn't currently support that.

Further, there's then no need to call skb_condense() in rxrpc_input_ack(),
so don't.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-53151?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53151?

Apply the vendor's patch.

## Is CVE-2026-53151 being exploited?

There is no known exploitation of CVE-2026-53151 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-2026-53151 and fix it if it is affected.

What it is: CVE-2026-53151 is a critical memory corruption vulnerability in Linux kernel, published on 25 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-2026-53151 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-2026-53151/ (Markdown: https://insights.sbomify.com/CVE-2026-53151/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53151
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53151
- OSV: https://osv.dev/vulnerability/CVE-2026-53151

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53151/
Summaries are generated and may contain mistakes; the official description above is the record.