PYSEC-2026-3547

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/aiohttp/PYSEC-2026-3547.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-3547
Aliases
Published
2026-08-04T11:34:46.955491Z
Modified
2026-08-04T14:30:14.644343094Z
Severity
  • 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N CVSS Calculator
Summary
AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate
Details

Summary

The client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated.

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

References

Affected packages

PyPI / aiohttp

Package

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.14.2

Affected versions

0.*
0.1
0.2
0.3
0.4
0.4.1
0.4.2
0.4.3
0.4.4
0.5.0
0.6.0
0.6.1
0.6.2
0.6.3
0.6.4
0.6.5
0.7.0
0.7.1
0.7.2
0.7.3
0.8.0
0.8.1
0.8.2
0.8.3
0.8.4
0.9.0
0.9.1
0.9.2
0.9.3
0.10.0
0.10.1
0.10.2
0.11.0
0.12.0
0.13.0
0.13.1
0.14.0
0.14.1
0.14.2
0.14.3
0.14.4
0.15.0
0.15.1
0.15.2
0.15.3
0.16.0
0.16.1
0.16.2
0.16.3
0.16.4
0.16.5
0.16.6
0.17.0
0.17.1
0.17.2
0.17.3
0.17.4
0.18.0
0.18.1
0.18.2
0.18.3
0.18.4
0.19.0
0.20.0
0.20.1
0.20.2
0.21.0
0.21.1
0.21.2
0.21.4
0.21.5
0.21.6
0.22.0a0
0.22.0b0
0.22.0b1
0.22.0b2
0.22.0b3
0.22.0b4
0.22.0b5
0.22.0b6
0.22.0
0.22.1
0.22.2
0.22.3
0.22.4
0.22.5
1.*
1.0.0
1.0.1
1.0.2
1.0.3
1.0.5
1.1.0
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
1.1.6
1.2.0
1.3.0
1.3.1
1.3.2
1.3.3
1.3.4
1.3.5
2.*
2.0.0rc1
2.0.0
2.0.1
2.0.2
2.0.3
2.0.4
2.0.5
2.0.6
2.0.7
2.1.0
2.2.0
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.3.0a1
2.3.0a2
2.3.0a3
2.3.0a4
2.3.0
2.3.1a1
2.3.1
2.3.2b2
2.3.2b3
2.3.2
2.3.3
2.3.4
2.3.5
2.3.6
2.3.7
2.3.8
2.3.9
2.3.10
3.*
3.0.0b0
3.0.0b1
3.0.0b2
3.0.0b3
3.0.0b4
3.0.0
3.0.1
3.0.2
3.0.3
3.0.4
3.0.5
3.0.6
3.0.7
3.0.8
3.0.9
3.1.0
3.1.1
3.1.2
3.1.3
3.2.0
3.2.1
3.3.0a0
3.3.0
3.3.1
3.3.2a0
3.3.2
3.4.0a0
3.4.0a3
3.4.0b1
3.4.0b2
3.4.0
3.4.1
3.4.2
3.4.3
3.4.4
3.5.0a1
3.5.0b1
3.5.0b2
3.5.0b3
3.5.0
3.5.1
3.5.2
3.5.3
3.5.4
3.6.0a0
3.6.0a1
3.6.0a2
3.6.0a3
3.6.0a4
3.6.0a5
3.6.0a6
3.6.0a7
3.6.0a8
3.6.0a9
3.6.0a11
3.6.0a12
3.6.0b0
3.6.0
3.6.1b3
3.6.1b4
3.6.1
3.6.2a0
3.6.2a1
3.6.2a2
3.6.2
3.6.3
3.7.0b0
3.7.0b1
3.7.0
3.7.1
3.7.2
3.7.3
3.7.4
3.7.4.post0
3.8.0a7
3.8.0b0
3.8.0
3.8.1
3.8.2
3.8.3
3.8.4
3.8.5
3.8.6
3.9.0b0
3.9.0b1
3.9.0rc0
3.9.0
3.9.1
3.9.2
3.9.3
3.9.4rc0
3.9.4
3.9.5
3.10.0b1
3.10.0rc0
3.10.0
3.10.1
3.10.2
3.10.3
3.10.4
3.10.5
3.10.6rc0
3.10.6rc1
3.10.6rc2
3.10.6
3.10.7
3.10.8
3.10.9
3.10.10
3.10.11rc0
3.10.11
3.11.0b0
3.11.0b1
3.11.0b2
3.11.0b3
3.11.0b4
3.11.0b5
3.11.0rc0
3.11.0rc1
3.11.0rc2
3.11.0
3.11.1
3.11.2
3.11.3
3.11.4
3.11.5
3.11.6
3.11.7
3.11.8
3.11.9
3.11.10
3.11.11
3.11.12
3.11.13
3.11.14
3.11.15
3.11.16
3.11.17
3.11.18
3.12.0b0
3.12.0b1
3.12.0b2
3.12.0b3
3.12.0rc0
3.12.0rc1
3.12.0
3.12.1rc0
3.12.1
3.12.2
3.12.3
3.12.4
3.12.6
3.12.7rc0
3.12.7
3.12.8
3.12.9
3.12.10
3.12.11
3.12.12
3.12.13
3.12.14
3.12.15
3.13.0
3.13.1
3.13.2
3.13.3
3.13.4
3.13.5
3.14.0
3.14.1

Database specific

source
"https://github.com/pypa/advisory-database/blob/main/vulns/aiohttp/PYSEC-2026-3547.yaml"