Bug 2454100 (CVE-2026-34519)

Summary: CVE-2026-34519 aiohttp: aiohttp: Header injection vulnerability via reason parameter
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
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
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Hardware: All   
OS: Linux   
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A flaw was found in aiohttp, an asynchronous HTTP client/server framework for Python. A remote attacker could exploit this vulnerability by controlling the 'reason' parameter during the creation of an HTTP response. This could allow the attacker to inject additional HTTP headers, potentially leading to unexpected behavior or further exploitation.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-04-01 21:02:26 UTC
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.