Answer in brief
CVE-2026-3298 records a High severity (CVSS 8.8) vulnerability in Out-of-bounds write in Windows asyncio.ProacterEventLoop.sock_recvfrom_into() when using nbytes. The current sources do not mark it as known exploited. The current feed maps Python Software Foundation/CPython (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-3298 records a High severity (CVSS 8.8) vulnerability in Out-of-bounds write in Windows asyncio.ProacterEventLoop.sock_recvfrom_into() when using nbytes. The current sources do not mark it as known exploited. The current feed maps Python Software Foundation/CPython (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. 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 Python Software Foundation/CPython (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Python Software Foundation/CPythongeneric | >=0 <3.13.14 || >=3.14.0a1 <3.14.5rc1 || >=3.15.0a1 <3.15.0b1 | 3.13.14, 3.14.5rc1, 3.15.0b1 |
Published upstream
Apr 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
The method "sock_recvfrom_into()" of "asyncio.ProacterEventLoop" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. This allowed for an out-of-bounds buffer write if data was larger than the buffer size. Non-Windows platforms are not affected.
Quoted source text, attributed separately from HOL analysis.
CVSS is 8.8. 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 Python Software Foundation/CPython (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Python Software Foundation/CPythongeneric | >=0 <3.13.14 || >=3.14.0a1 <3.14.5rc1 || >=3.15.0a1 <3.15.0b1 | 3.13.14, 3.14.5rc1, 3.15.0b1 |
Published upstream
Apr 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
The method "sock_recvfrom_into()" of "asyncio.ProacterEventLoop" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. This allowed for an out-of-bounds buffer write if data was larger than the buffer size. Non-Windows platforms are not affected.
Quoted source text, attributed separately from HOL analysis.