CVE-2026-34520

criticalpriority · track · 0EPSS 0.005 · 40 %ileDEEUFRNLRUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.46% (40th) EPSS
CVSS 9.1 · critical
Is it mine?
19 products
Check your exposure
Who says so?
8 sources
cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, the C parser (the default for most installs) accepted null bytes and control characters in response headers. This issue has been patched in version 3.13.4.

01

cvss

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

9.1
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–critical · 2.7–9.1

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Hsecondary · OSV
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Hsecondaryexploitability 3.9 · impact 5.2
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Hsecondary · NCSC-NL NL
v3.19.1criticalAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Hsecondary · FSTEC (BDU) RU
v4.02.7lowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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 · security-advisories@github.com
v4.02.7lowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:Usecondary · ENISA EU
v4.02.7lowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-113USCWE-113USCWE-113USCWE-113US
04

affected products (19)

Products and version ranges known to be affected.

05

advisories (7)

Vendor and ecosystem advisories describing this.

  • NCSC-2026-0256Kwetsbaarheden verholpen in Oracle CommunicationsNL2026-07-22csaf · ncsc_nlNL

    Oracle heeft kwetsbaarheden verholpen in Communications producten en onderliggende third party software. Het betreft een totaal van 213 kwetsbaarheden, waarvan 67 zich bevinden in Oracle producten en 146 in third-party producten waar eerder updates voor zijn verschenen en welke in deze Oracle updates zijn verwerkt.

  • WID-SEC-W-2026-2437Oracle Communications: Mehrere SchwachstellenDeutsch2026-07-21csaf · cert_bundDE

    Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Communications ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

  • WID-SEC-W-2026-2451Oracle Siebel CRM: Mehrere SchwachstellenDeutsch2026-07-21csaf · cert_bundDE

    Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Siebel CRM ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

  • 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-63hf-3vf5-4wqfAIOHTTP's C parser (llhttp) accepts null bytes and control characters in response header values - header injection/security bypass2026-04-01ghsa · osvUS

    ### Summary The C parser (the default for most installs) accepted null bytes and control characters in request headers. ### Impact An attacker could send header values that are interpreted differently than expected due to the presence of control characters. For example, `request.url.origin()` may return a different value than the raw Host header, or what a reverse proxy interpreted it as., potentially resulting in some kind of security bypass. ----- Patch: https://github.com/aio-libs/aiohttp/commit/9370b9714a7a56003cacd31a9b4ae16eab109ba4

  • CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
  • PYSEC-2026-21022026-04-01vendor · osvUS

    AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, the C parser (the default for most installs) accepted null bytes and control characters in response headers. This issue has been patched in version 3.13.4.

06

also known as (7)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bduosvcert_bundncsc_nlnvdcertfrNVDCVE.orgMITRE
published 2026-04-01modified 2026-10-26
08

references (9)

External citations — patches, advisories, analysis.

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