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Vulnerabilities

Vulnerability · CVE-2025-0686

A flaw was found in grub2.

Published Mar 3, 2025 · catalog updated Oct 21, 2026 · A flaw was found

Check if you run it

No confirmed exploitation is on record for CVE-2025-0686. EPSS is 0.28%. Act only if a listed version of A flaw was found is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (A flaw was found).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium6.4
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.28%
Remediation
Version ranges on file
Affected products
cpe gnu/grub2

A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passing secure boot protections.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe gnu/grub2<= 2.12

How to fix CVE-2025-0686

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-0686. EPSS is 0.28%. Act only if a listed version of A flaw was found is installed.

Which versions are affected?

Compare what you have installed with <= 2.12. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-787: Out-of-bounds Write. EPSS 0.28%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 3, 2025 · NIST NVD

    Detected

    A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc()

  2. Oct 21, 2026 · NIST NVD

    Updated

    A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc()

Sources

  • CVE.orgVulnerability recordCVE-2025-0686

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-0686

    30-day exploitation probability 0.28%

    first.org
  • NIST NVDVulnerability recordCVE-2025-0686

    A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A malicious

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 21, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.