CVE-2025-61663: gnu grub2 Expired Pointer Dereference
Vulnerability summary
CVE-2025-61663 is a medium (CVSS 4.9) Expired Pointer Dereference vulnerability in gnu grub2. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 2.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 11 · Related 11Timeline
- 18-11-2025PublishedVulnerability first disclosed.
- 01-09-2026Last modifiedVulnerability information updated.
Description
A vulnerability has been identified in the GRUB2 bootloader's normal command that poses an immediate Denial of Service (DoS) risk. This flaw is a Use-after-Free issue, caused because the normal command is not properly unregistered when the module is unloaded. An attacker who can execute this command can force the system to access memory locations that are no longer valid. Successful exploitation leads directly to system instability, which can result in a complete crash and halt system availability. Impact on the data integrity and confidentiality is also not discarded.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated4.9MediumCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
- OSV · DebianEcosystem advisory · calculated4.9MediumCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
- NVDNIST4.9MediumCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS trend
Probability
0.14%
Chance of exploitation in the next 30 days
Percentile
3%
Versus all other CVEs
30-day change
+0.01 pp
From 0.13% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu3 products
- grub2All versions (No fix recorded)
- grub2-signedAll versions (No fix recorded)
- grub2-unsignedAll versions (No fix recorded)
Debian1 product
- grub2All versions (No fix recorded) | < 2.14-1
Gnu1 product
- grub2≤ 2.14
3 vendors · 5 products
