CVE-2026-34525

mediumpriority · track · 21EPSS 0.004 · 32 %ileDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.39% (32nd) EPSS
CVSS 5.3 · medium
Is it mine?
9 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-23

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

01

cvss

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

6.3
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.7–6.3

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4
v3.15.3mediumAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nsecondary · FSTEC (BDU) RU
v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nsecondary · OSV
v4.06.3mediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:Nsecondary · ENISA EU
v4.06.3mediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/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
v4.01.7lowCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/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

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USCWE-20USCWE-20USCWE-444USCWE-444USCWE-444US
03

affected products (9)

Products and version ranges known to be affected.

04

advisories (3)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-2933Splunk SOAR: Mehrere SchwachstellenDeutsch2026-08-19csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Splunk SOAR ausnutzen, um Sicherheitsvorkehrungen zu umgehen, um Informationen offenzulegen, um Dateien zu manipulieren, um einen SQL-Injection Angriff durchzuführen, um einen Cross-Site Scripting Angriff durchzuführen, und um beliebigen Programmcode auszuführen.

  • GHSA-c427-h43c-vf67AIOHTTP accepts duplicate Host headers2026-04-01ghsa · osvUS

    ### Summary Multiple Host headers were allowed in aiohttp. ### Impact Mostly this doesn't affect aiohttp security itself, but if a reverse proxy is applying security rules depending on the target Host, it is theoretically possible that the proxy and aiohttp could process different host names, possibly resulting in bypassing a security check on the proxy and getting a request processed by aiohttp in a privileged sub app when using `Application.add_domain()`. ----- Patch: https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349 Patch: https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000

  • PYSEC-2026-21032026-04-01vendor · osvUS

    AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

05

also known as (6)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bduosvcert_bundnvdNVDCVE.orgMITRE
published 2026-04-01modified 2026-06-17
07

references (11)

External citations — patches, advisories, analysis.

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