Answer in brief
CVE-2021-33626 records a Unknown severity vulnerability in CVE Program Container. The current sources do not mark it as known exploited. The current feed maps n/a/n/a (generic), Siemens/RUGGEDCOM APE1808 - BIOS (generic), Siemens/SIMATIC Field PG M5 (generic), Siemens/SIMATIC Field PG M6 (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps n/a/n/a (generic), Siemens/RUGGEDCOM APE1808 - BIOS (generic), Siemens/SIMATIC Field PG M5 (generic), Siemens/SIMATIC Field PG M6 (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| n/a/n/ageneric | n/a | Not reported |
| Siemens/RUGGEDCOM APE1808 - BIOSgeneric | >=0 <V1.0.202N | V1.0.202N |
| Siemens/SIMATIC Field PG M5generic | >=0 <V22.01.10 | V22.01.10 |
| Siemens/SIMATIC Field PG M6generic | >=0 <V26.01.13 | V26.01.13 |
| Siemens/SIMATIC IPC127Egeneric | >=0 <V27.01.09 | V27.01.09 |
| Siemens/SIMATIC IPC227Ggeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC277Ggeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC277G PROgeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC327Ggeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC377Ggeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC427Egeneric | >=0 <V21.01.17 | V21.01.17 |
| Siemens/SIMATIC IPC477Egeneric | >=0 <V21.01.17 | V21.01.17 |
| Siemens/SIMATIC IPC477E PROgeneric | >=0 <V21.01.17 | V21.01.17 |
| Siemens/SIMATIC IPC627Egeneric | >=0 <V25.02.12 | V25.02.12 |
| Siemens/SIMATIC IPC647Egeneric | >=0 <V25.02.12 | V25.02.12 |
| Siemens/SIMATIC IPC677Egeneric | >=0 <V25.02.12 | V25.02.12 |
| Siemens/SIMATIC IPC847Egeneric | >=0 <V25.02.12 | V25.02.12 |
| Siemens/SIMATIC ITP1000generic | >=0 <V23.01.10 | V23.01.10 |
| Siemens/SIPLUS IPC427Egeneric | >=0 <V21.01.17 | V21.01.17 |
Published upstream
Oct 1, 2021
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 11, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2021-33626 records a Unknown severity vulnerability in CVE Program Container. The current sources do not mark it as known exploited. The current feed maps n/a/n/a (generic), Siemens/RUGGEDCOM APE1808 - BIOS (generic), Siemens/SIMATIC Field PG M5 (generic), Siemens/SIMATIC Field PG M6 (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps n/a/n/a (generic), Siemens/RUGGEDCOM APE1808 - BIOS (generic), Siemens/SIMATIC Field PG M5 (generic), Siemens/SIMATIC Field PG M6 (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| n/a/n/ageneric | n/a | Not reported |
| Siemens/RUGGEDCOM APE1808 - BIOSgeneric | >=0 <V1.0.202N | V1.0.202N |
| Siemens/SIMATIC Field PG M5generic | >=0 <V22.01.10 | V22.01.10 |
| Siemens/SIMATIC Field PG M6generic | >=0 <V26.01.13 | V26.01.13 |
| Siemens/SIMATIC IPC127Egeneric | >=0 <V27.01.09 | V27.01.09 |
| Siemens/SIMATIC IPC227Ggeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC277Ggeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC277G PROgeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC327Ggeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC377Ggeneric | >=0 <V28.01.04 | V28.01.04 |
| Siemens/SIMATIC IPC427Egeneric | >=0 <V21.01.17 | V21.01.17 |
| Siemens/SIMATIC IPC477Egeneric | >=0 <V21.01.17 | V21.01.17 |
| Siemens/SIMATIC IPC477E PROgeneric | >=0 <V21.01.17 | V21.01.17 |
| Siemens/SIMATIC IPC627Egeneric | >=0 <V25.02.12 | V25.02.12 |
| Siemens/SIMATIC IPC647Egeneric | >=0 <V25.02.12 | V25.02.12 |
| Siemens/SIMATIC IPC677Egeneric | >=0 <V25.02.12 | V25.02.12 |
| Siemens/SIMATIC IPC847Egeneric | >=0 <V25.02.12 | V25.02.12 |
| Siemens/SIMATIC ITP1000generic | >=0 <V23.01.10 | V23.01.10 |
| Siemens/SIPLUS IPC427Egeneric | >=0 <V21.01.17 | V21.01.17 |
Published upstream
Oct 1, 2021
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 11, 2026
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.
Quoted source text, attributed separately from HOL analysis.