CVE-2026-97631: Pre-boot RCE in EDK II PXE driver
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.6%
EPSS score, percentile 50.4 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 9.5 Critical
CVSS v4.0 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- edk2-stable202608 and earlier
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | edk2-stable202608 and earlier |
Versions not listed are: unaffected.
Source: CVE List, as of . About the data.
About this vulnerability
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.
Summary: CVE record, as of .
- CISA has not added CVE-2026-97631 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 22 Oct 2026.
- The CVE record carries a CVSS v4.0 base score of 9.5 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.6% (percentile 50.4), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- The credits in the CVE record name Anthropic (Claude) as finder.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
Pre-boot RCE in EDK II PXE driver
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.
Source: CVE List, as of . About the data.
Weakness
CWE-120, CWE-131, CWE-787
- 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
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |