CVE-2026-97876
Bypass of GRUB lockdown restriction in Secure Boot mode via serial command MMIO base address
02 Description
Bypass of GRUB lockdown restriction in Secure Boot mode via serial command MMIO base address
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 0.11% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 1.3% of scored records. A rank, not a probability.
- NVD base score
- 6.4 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Awaiting Analysis. NVD last modified this record on 2026-10-02.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-10-02 10:34Z27 DAYS AGO
- Last updated
- 2026-10-02 17:45Z26 DAYS AGO
- Reserved
- 2026-09-25
- Assigning CNA
- canonical
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.4)
- CNA CVSS vector
- CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-822Untrusted Pointer DereferenceBase
- Data version
- 5.2
- Document digest
- 2938ef1d7c54631ee6e229f9b368adaed4ec4e229c9bd8ed559f42df4ef95af1
05 Affected products
06 References
- www.openwall.comhttps://www.openwall.com/lists/oss-security/2026/09/13/5
- gitlab.freedesktop.orghttps://gitlab.freedesktop.org/gnu-grub/grub/-/commit/26beaa3b2720fefdc4d04c1ae209b776fe6848d6
07 Fixed in
Debian 13
- grub2 No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- grub2 Fixed in 2.14-4
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- grub2-signed No fix yet
- grub2-unsigned No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- grub2-signed No fix yet
- grub2-unsigned No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- grub2-signed No fix yet
- grub2-unsigned No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- grub2-signed No fix yet
- grub2-unsigned No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- grub2-signed No fix yet
- grub2-unsigned No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- grub2-signed No fix yet
- grub2-unsigned No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.10
- grub2-signed No fix yet
- grub2-unsigned No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- grub2 No fix yet
- grub2-signed No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.