CVE-2025-26403: intel-microcode Out-of-bounds Write
CVSS: 7.2v3.1HighDeferred
AliasesALPINE-CVE-2025-26403UBUNTU-CVE-2025-26403DEBIAN-CVE-2025-26403
Published 12-08-2025Last modified 26-02-2026
Vulnerability summary
CVE-2025-26403 is a high (CVSS 7.2) Out-of-bounds Write vulnerability in intel-microcode. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 3.1% of scored vulnerabilities.
CVSS score
7.2/10
010
High · v3.1 (NVD)EPSS score
0.14%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 10 · Related 7Timeline
- 12-08-2025PublishedVulnerability first disclosed.
- 26-02-2026Last modifiedVulnerability information updated.
Description
Out-of-bounds write in the memory subsystem for some Intel(R) Xeon(R) 6 processors when using Intel(R) SGX or Intel(R) TDX may allow a privileged user to potentially enable escalation of privilege via local access.
CVSS metrics
7 scores · 5 sources · 2 versionsMedium 4.5Preferred score · CVE.org (CNA)
CVSS:4.0/AV:L/AC:H/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:NSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated4.5MediumCVSS:4.0/AV:L/AC:H/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated4.5MediumCVSS:4.0/AV:L/AC:H/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
- OSV · DebianEcosystem advisory · calculated4.5MediumCVSS:4.0/AV:L/AC:H/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVDNIST4.5MediumCVSS:4.0/AV:L/AC:H/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
High 7.2Preferred score · NVD (NIST)
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:NSourcesAll 2 agree
- OSV · UbuntuEcosystem advisory · calculated7.2HighCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N
EPSS trend
Probability
0.14%
Chance of exploitation in the next 30 days
Percentile
3%
Versus all other CVEs
30-day change
0.00 pp
From 0.14% on 19-09-2026
19-09-202619-10-2026
EPSS score0.14%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- intel-ucode< 20250812-r0
Debian1 product
- intel-microcode< 3.20250812.1~deb12u1 | < 3.20250812.1~deb13u1 | < 3.20250812.1
Ubuntu1 product
- intel-microcodeAll versions (No fix recorded) | < 3.20250812.0ubuntu0.16.04.1+esm1 | < 3.20250812.0ubuntu0.18.04.1+esm1 | < 3.20250812.0ubuntu0.20.04.1+esm1 | < 3.20250812.0ubuntu0.22.04.1 | < 3.20250812.0ubuntu0.24.04.1 | < 3.20250812.0ubuntu0.25.10.1
3 vendors · 3 products
