# CVE-2025-0689: Grub2: udf: heap based buffer overflow in grub_udf_read_block() may lead to arbitrary code execution

Status: published. Published: 2025-03-03. Updated: 2026-11-05.

When reading data from disk, the grub's UDF filesystem module utilizes the user controlled data length metadata to allocate its internal buffers. In certain scenarios, while iterating through disk sectors, it assumes the read size from the disk is always smaller than the allocated buffer size which is not guaranteed. A crafted filesystem image may lead to a heap-based buffer overflow resulting in critical data to be corrupted, resulting in the risk of arbitrary code execution by-passing secure boot protections.

## Remediation

- workaround: Do not run grub2 in an untrusted environment, specifically with a UDF file system image. (source: CNA: redhat)

## Affected products and versions

-  /  (grub2): ≥ 0; ≤ 2.12 (affected, semver). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (grub2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (grub2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (grub2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (grub2): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 7.8 (high); CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.50% as of 2026-11-05; percentile 42.84%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-120

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2025-0689 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2346122 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://lists.gnu.org/archive/html/grub-devel/2025-02/msg00024.html (CNA: redhat)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2025-0689; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2025-0689; retrieved 2026-11-05; source updated Not reported

Revision: a475543a4b1e3e17d01eea70387816c1a9ca9e15f967d66976ee4892aae882f3

Canonical: https://y2.dev/cve/CVE-2025-0689

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.