Answer in brief
CVE-2025-0677 records a Medium severity (CVSS 6.4) vulnerability in Grub2: ufs: integer overflow may lead to heap based out-of-bounds write when handling symlinks. The current sources do not mark it as known exploited. The current feed maps grub2 (generic), Red Hat/openshift/ose-rhel-coreos-9 (generic), Red Hat/rhcos (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps grub2 (generic), Red Hat/openshift/ose-rhel-coreos-9 (generic), Red Hat/rhcos (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| grub2generic | >=0 <=2.12 | Not reported |
| Red Hat/openshift/ose-rhel-coreos-9generic | * | Not reported |
| Red Hat/rhcosgeneric | * | Not reported |
Published upstream
Feb 19, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 25, 2026
A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the file content, however, it fails to check if the symlink data size has overflown. When this occurs, grub_malloc() may be called with a smaller value than needed. When further reading the data from the disk into the buffer, the grub_ufs_lookup_symlink() function will write past the end of the allocated size. An attack can leverage this by crafting a malicious filesystem, and as a result, it will corrupt data stored in the heap, allowing for arbitrary code execution used to by-pass secure boot mechanisms.
Quoted source text, attributed separately from HOL analysis.