# CVE-2026-53245: net/802/mrp: fix vector attribute parsing in mrp_pdu_parse_vecattr

> A flaw in Linux kernel MRP parsing allows attackers to corrupt memory or cause denial of service via malformed network packets.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 25 Jun 2026
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-90380, BELL-CVE-2026-53245, DEBIAN-CVE-2026-53245, GHSA-5mw9-5f6m-q724, ROOT-OS-DEBIAN-11-CVE-2026-53245, ROOT-OS-DEBIAN-12-CVE-2026-53245, ROOT-OS-UBUNTU-2204-CVE-2026-53245, ROOT-OS-UBUNTU-2404-CVE-2026-53245, UBUNTU-CVE-2026-53245

## What is CVE-2026-53245?

CVE-2026-53245 is a medium-severity memory corruption vulnerability in Linux kernel, published on 25 Jun 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/802/mrp: fix vector attribute parsing in mrp_pdu_parse_vecattr

In mrp_pdu_parse_vecattr(), vector attribute events are encoded three
per byte and valen tracks the number of events left to process.

The parser decrements valen after processing the first and second events
from each event byte, but not after processing the third one. When valen
is exactly a multiple of three, the loop continues after the last valid
event and consumes the next byte as a new event byte, applying a
spurious event to the MRP applicant state.

Additionally, when valen is zero the parser unconditionally consumes
attrlen bytes as FirstValue and advances the offset, even though per
IEEE 802.1ak a VectorAttribute with only a LeaveAllEvent has valen of
zero and no FirstValue or Vector fields. This corrupts the offset for
subsequent PDU parsing.

Also, when valen exceeds three the loop crosses byte boundaries but
the attribute value is not incremented between the last event of one
byte and the first event of the next. This causes the first event of
the next byte to use the same attribute value as the third event
rather than the next consecutive value.

Decrement valen after processing the third event, skip FirstValue
consumption when valen is zero, and increment the attribute value at
the end of each loop iteration.

## Which versions are affected by CVE-2026-53245?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53245?

Apply the vendor's patch.

## Is CVE-2026-53245 being exploited?

There is no known exploitation of CVE-2026-53245 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-2026-53245 and fix it if it is affected.

What it is: CVE-2026-53245 is a medium-severity memory corruption vulnerability in Linux kernel, published on 25 Jun 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-2026-53245 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-2026-53245/ (Markdown: https://insights.sbomify.com/CVE-2026-53245/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53245
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53245
- OSV: https://osv.dev/vulnerability/CVE-2026-53245

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53245/
Summaries are generated and may contain mistakes; the official description above is the record.