Home/CVE/AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.0, attacker-controlled inp
CVE
CVE-2026-50269
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.0, attacker-controlled inp
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.0, attacker-controlled input included into multipart/payload headers can be used to modify a request to inject additional headers or similar. In the unlikely situation that an application is passing user-controlled strings into MultipartWriter.append(headers=...) or Payload.headers, then an attacker may be able to modify the request to inject headers or change the contents of the request.
This vulnerability is fixed in 3.14.0.
Schedule remediation
- SSVC automatable: yes - attacks can be scripted at scale
- ⚠ NVD has not scored this CVE yet - manual triage required (common for recent CVEs)
No Sigma yet — build one →
YARA rules0
Look this up elsewhere - one-click external pivots
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How to read a CVE - triage first, then detect and patch
This page is every public fact about CVE-2026-50269, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.
Triage: should I act now? Four signals, and they are not interchangeable:
CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked.
EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal.
CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score.
Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.
How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.
Then what - two workflows:
Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits.
PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.
Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).
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Severity & exploitation scoring
EPSS exploitation probability
n/a
No EPSS score in our data for this CVE. EPSS is published daily for scored CVEs - a very new, reserved, or rejected CVE may not have one yet.
CVSS metric silhouette
No structured CVSS vector for this CVE. Older entries often have only a numeric base score - the metric breakdown radar requires a full
AV:_/AC:_/... vector string published by NVD.SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Tech impact
partial
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ATT&CK techniques
1Techniques this CVE enables. Pills with a solid outline are high confidence - named directly in ATT&CK or Nuclei, or human-curated by CTID; the rest are inferred from the weakness type using MITRE's CVE Mapping Methodology and the CWE → CAPEC chain. Broad, generic-weakness guesses are filtered out. A small N× marks a technique that N independent sources agree on.
▤ Build a SIEM detection for these techniques▤
CAPEC attack patterns
6Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.
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Weakness Classification
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Affected Packages
1Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
PyPI
aiohttp
LOW
fixed in 3.14.0
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Related CVEs
8CVEs linked to this one by a shared weakness (CWE) or affected product - joins on data already in the engine, with the reason shown per row. Not a guess.
CVE-2007-5595
CRLF injection vulnerability in the drupal_goto function in includes/common.inc ...
same CWE-113
CVE-2015-0733
CRLF injection vulnerability in the HTTP Header Handler in Digital Broadband Del...
same CWE-113
CVE-2015-1445
HTTP header injection in the httpd package in fli4l before 3.10.1 and 4.0 before...
same CWE-113
HIGH
CVE-2016-5699
CRLF injection vulnerability in the HTTPConnection.putheader function in urllib2...
same CWE-113
MEDIUM
CVE-2007-0892
CRLF injection vulnerability in phpMyVisites before 2.2 allows remote attackers ...
same CWE-93
CVE-2014-9564
CRLF injection vulnerability in IBM Flex System EN6131 40Gb Ethernet and IB6131 ...
same CWE-93
MEDIUM
CVE-2014-2017
CRLF injection vulnerability in OXID eShop Professional Edition before 4.7.11 an...
1
same CWE-93
MEDIUM
CVE-2014-9563
CRLF injection vulnerability in the web-based management (WBM) interface in Unif...
same CWE-93
MEDIUM
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Fixed versions by distribution
1The package version that resolves this CVE on each Linux distribution, from the vendor’s published security data. fixed in shows a patched version exists; open means the package is listed as affected with no fix yet.
alpine edgepy3-aiohttp fixed in 3.14.1-r0
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References & Sources
2Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.