Bug 2454094 (CVE-2026-34520)

Summary: CVE-2026-34520 aiohttp: AIOHTTP: Header injection vulnerability due to improper character handling
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: adudiak, alinfoot, anpicker, anthomas, bbrownin, bdettelb, bparees, caswilli, dfreiber, doconnor, drow, dschmidt, dtrifiro, ebourniv, ehelms, erezende, ggainey, hasun, jburrell, jdobes, jfula, jkoehler, jlanda, jmitchel, jowilson, jsamir, juwatts, jwong, kaycoth, kshier, lgallett, lichen, ljawale, lphiri, luizcosta, mhulan, nmoumoul, nweather, nyancey, omaciel, ometelka, orabin, osousa, pakotvan, pbohmill, pcreech, ptisnovs, rbobbitt, rbryant, rchan, sbunciak, simaishi, smallamp, smcdonal, stcannon, sthirugn, syedriko, teagle, tmalecek, ttakamiy, vkumar, weaton, xdharmai, xialiu, yguenane, zzhou
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in AIOHTTP, an asynchronous HTTP client/server framework for Python. The default C parser incorrectly processed null bytes and control characters present in HTTP response headers. This vulnerability could allow a remote attacker to inject malicious data into these headers, potentially leading to unexpected application behavior or security bypasses.
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-04-01 21:01:53 UTC
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.