CVE-2026-34514

MEDIUM

5.3

CVSS v3

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the content_type parameter in aiohttp could use this to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.

CWE-113

How to fix

Remediation Available

python-aiohttpDebian

Fixed in:3.7.4-1+deb11u2CVE-2026-34514

Fixed in:3.13.5-1CVE-2026-34514

python-aiohttpUbuntu

Fixed in:0.20.2-1ubuntu0.1~esm1USN-8591-1

Fixed in:3.0.1-1ubuntu0.1~esm7USN-8591-1

Fixed in:3.6.2-1ubuntu1+esm6USN-8591-1

Fixed in:3.8.1-4ubuntu0.2+esm3USN-8591-1

Fixed in:3.9.1-1ubuntu0.1+esm3USN-8591-1

python3-aiohttpUbuntu

Fixed in:0.20.2-1ubuntu0.1~esm1USN-8591-1

Fixed in:3.0.1-1ubuntu0.1~esm7USN-8591-1

Fixed in:3.6.2-1ubuntu1+esm6USN-8591-1

Fixed in:3.8.1-4ubuntu0.2+esm3USN-8591-1

Fixed in:3.9.1-1ubuntu0.1+esm3USN-8591-1

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Exploit Intelligence

0.32%probability of exploitation in 30 days

24thpercentile

Low risk: more likely to be exploited than 24% of all known CVEs.

References

Patch2

Release Notes1

github.com

Related Vulnerabilities

Other CWE-113 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2022-37436	Medium	5.3	58%	-	Fix
CVE-2024-52875	High	8.8	30%	-	-
CVE-2016-5699	Medium	6.1	10%	-	Fix
CVE-2016-8024	High	8.1	8.7%	-	-
CVE-2017-17742	Medium	5.3	5.6%	-	Fix
CVE-2016-5325	Medium	6.1	4.1%	-	Fix

Common questions

How do I fix CVE-2026-34514?

Published advisories record a fix for 3 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-34514 being actively exploited?

Not that we know of. CVE-2026-34514 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.32% is the estimated probability that it will be exploited in the next 30 days. That is higher than 24% of all scored CVEs.

How severe is CVE-2026-34514?

CVE-2026-34514 has a CVSS v3 base score of 5.3, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-34514 affect?

Published advisories record a fix for python-aiohttp (Debian), python-aiohttp (Ubuntu), python3-aiohttp (Ubuntu). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-15.