CVE-2026-97631: Pre-boot RCE in EDK II PXE driver
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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.
Description quoted from the CVE record (assigned by TianoCore, published 2026-10-22).
Weakness: CWE-120 Buffer Copy without Checking Size of Input (‘Classic Buffer Overflow’); CWE-131 Incorrect calculation of buffer size; CWE-787 Out-of-bounds write
How it can be exploited
Exploitable over the network with low attack complexity only when specific conditions are present needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: total.
Public exploit evidence (Exploit Observer)
Exploit Observer evidence for this CVE has not been fetched yet.
Live scores
- EPSS
- 0.006
low predicted chance of attack - VEDAS
- 0.512
some exploit evidence - On CISA KEV
- Not listed
- Detection rule
- None yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| TianoCore EDK2 (NetworkPkg) | up to and including edk2-stable202608 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
Advisories on this CVE
- TianoCore EDK II PXE driver pre-boot RCE (CVE-2026-97631): fixed on main, in no stable release yet (full advisory)
- TianoCore EDK II: pre-boot RCE in the PXE network-boot driver, unpatched in any stable release (CVE-2026-97631) (22 Oct 2026)
References
Other references
- https://github.com/tianocore/edk2/security/advisories/GHSA-99cj-7hg9-mp4m
- https://arstechnica.com/security/2026/10/code-execution-flaw-in-uefi-firmware-threatens-most-servers-on-planet-earth/
- https://news.ycombinator.com/item?id=50265393
- https://github.com/microsoft/mu_basecore/pull/1990
- https://github.com/microsoft/mu_basecore/pull/1989
- http://www.openwall.com/lists/oss-security/2026/10/28/4
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS). Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.