CVE-2025-0677Grub2: ufs: integer overflow may lead to heap based out-of-bounds write when handling symlinks
- 6.4MediumCVSS base score
- 0.33%Exploitation in 30 daysEPSS · top 74% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By redhat
- 27 days later
· 27 days later
Published
- 21 months later
· 21 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Medium6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Deferred | 3.1 | Medium6.4 | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.33% · top 74% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.4.
Affected products
grub2
- affected ≤ 2.12
Red Hat · Red Hat Enterprise Linux 10
- unaffected 1:2.12-15.el10_0 – < *
Red Hat · Red Hat Enterprise Linux 9
- unaffected 1:2.06-104.el9_6 – < *
Red Hat · Red Hat Enterprise Linux 7
All versions: unknown
Red Hat · Red Hat Enterprise Linux 8
All versions: unknown
Red Hat · Red Hat OpenShift Container Platform 4
All versions: affected
What to do
Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
References
References5
- RHSA-2025:16154 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2025:6990 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2025-0677 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2346116 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://lists.gnu.org/archive/html/grub-devel/2025-02/msg00024.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-4654 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-0677)Record last updated .