AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate
Published Jul 30, 2026 · Updated Nov 3, 2026
Original summary
Normalized public record · Updated Nov 3, 2026
AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
The client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated.
Potential impact
A client may unexpectedly decompress WebSocket frames when explicitly opted out. This could lead to additional CPU/memory consumption, but is unlikely to be a significant issue unless a zip bomb vulnerability or similar is also present. --- Patch: https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- LOW
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Jul 30, 2026 · Last refreshed Nov 3, 2026