7.8

CVE-2021-33626: insyde insydeh2o

CVSS: 7.8v3.1HighModified
Published 01-10-2021Last modified 11-08-2026
Open JSON

Vulnerability summary

CVE-2021-33626 is a high (CVSS 7.8) vulnerability in insyde insydeh2o. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 22.1% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (NVD)
EPSS score
0.31%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 01-10-2021
    PublishedVulnerability first disclosed.
  2. 11-08-2026
    Last modifiedVulnerability information updated.

Description

A vulnerability exists in SMM (System Management Mode) branch that registers a SWSMI handler that does not sufficiently check or validate the allocated buffer pointer(QWORD values for CommBuffer). This can be used by an attacker to corrupt data in SMRAM memory and even lead to arbitrary code execution.

CVSS metrics

2 scores · 1 source · 2 versions

EPSS trend

Probability

0.31%

Chance of exploitation in the next 30 days

Percentile

22%

Versus all other CVEs

30-day change

0.00 pp

From 0.31% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.31%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Siemens16 products
Insyde1 product
  • insydeh2o≥ 5.3, < 5.34.44 | ≥ 5.2, < 5.25.44 | ≥ 5.1, < 5.16.25 | ≥ 5.4, < 5.42.44 | ≥ 5.3, < 5.35.25 | ≥ 5.2, < 5.26.25 | ≥ 5.4, < 5.43.25

2 vendors · 17 products

References

6 links