by Kastro
Paper/Archive/CVE-2026-97631

CVE-2026-97631

TianoCore EDK2 — Pre-boot RCE in EDK II PXE driver

EPSS 0.6%CVSS 9.5
critical.is priorityof 100
39
CVSS 9.5 (CNA)9.5 / 10 × 3028.5Not in CISA KEV+300.0EPSS percentile 50.4.504 × 2010.1No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

EDK2 contains a vulnerability in BIOS where a user may cause “Out-of-bounds Write”, Classic Buffer Overflow, and “Incorrect Calculation of Buffer Size” by remote access. Successful exploitation of this vulnerability can lead to arbitrary code execution. It could also impact Confidentiality, Integrity, and Availability.

Affected

ProductAffectedFixed inSource
EDK2≤ edk2-stable202608–CNA

Scores by source

TianoCore (CNA)9.5CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

References

refgithub.com/tianocore/edk2/security/advisories/GHSA-99cj-7hg9-mp4mrefarstechnica.com/security/2026/10/code-execution-flaw-in-uefi-firmware-threatens-most-servers-on-planet-earthrefnews.ycombinator.com/item?id=50265393refgithub.com/microsoft/mu_basecore/pull/1990refgithub.com/microsoft/mu_basecore/pull/1989refopenwall.com/lists/oss-security/2026/10/28/4