CVE-2026-59881

mediumpriority · track · 0EPSS 0.005 · 44 %ileEUFRUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.52% (44th) EPSS
CVSS 6.9 · medium
Is it mine?
2 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · osv · certfr

EPSS · scored 2026-10-27

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption. This issue is fixed in version 3.14.2.

01

cvss

Technical severity, 0–10. One row per scoring source.

6.9
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.7–6.9

v4.06.9mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:Nsecondary · ENISA EU
v4.06.9mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · security-advisories@github.com
v4.02.7lowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-20US
04

affected products (2)

Products and version ranges known to be affected.

05

advisories (3)

Vendor and ecosystem advisories describing this.

  • GHSA-mq44-7p77-q5h7AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate2026-08-03ghsa · osvUS

    ### 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

  • CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
  • PYSEC-2026-3547AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate2026-08-04vendor · osvUS

    ### 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

06

also known as (6)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdosvcertfrNVDCVE.orgMITRE
published 2026-07-30modified 2026-10-23
09

references (12)

External citations — patches, advisories, analysis.

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