CVE-2026-111749
published 2026-10-19CVE-2026-111749: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Host-Only scope on an existing parent-domain cookie can be…
PriorityP417low2.3CVSS 4.0
AVNACLATPPRNUIPVCLVILVANSCNSINSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
EPSS
0.29%
20.9th percentile
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Host-Only scope on an existing parent-domain cookie can be removed by a subdomain. A user who accesses an untrusted subdomain can consequently have host-only protections stripped from cookies, although impact is limited when applications do not reflect those cookies to a browser. This issue is fixed in version 3.14.4.
Affected
124 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| aio-libs | aiohttp | < 3.14.4 | 3.14.4 |
| aiohttp | aiohttp | >= 0 < 3.14.4 | 3.14.4 |
| ansible-automation-platform-24 | controller-rhel8 | — | — |
| ansible-automation-platform-24 | lightspeed-rhel8 | — | — |
| ansible-automation-platform-25 | controller-rhel8 | — | — |
| ansible-automation-platform-25 | lightspeed-chatbot-rhel8 | — | — |
| ansible-automation-platform-25 | lightspeed-rhel8 | — | — |
| ansible-automation-platform-26 | ansible-dev-tools-rhel9 | — | — |
| ansible-automation-platform-26 | controller-rhel9 | — | — |
| ansible-automation-platform-26 | de-minimal-rhel9 | — | — |
| ansible-automation-platform-26 | de-supported-rhel9 | — | — |
| ansible-automation-platform-26 | ee-minimal-rhel9 | — | — |
| ansible-automation-platform-26 | ee-supported-rhel9 | — | — |
| ansible-automation-platform-26 | hub-rhel9 | — | — |
| ansible-automation-platform-26 | lightspeed-chatbot-rhel9 | — | — |
| ansible-automation-platform-26 | lightspeed-rhel9 | — | — |
| ansible-automation-platform-26 | platform-resource-runner-rhel9 | — | — |
| ansible-automation-platform-27 | controller-rhel9 | — | — |
| ansible-automation-platform-27 | de-minimal-rhel9 | — | — |
| ansible-automation-platform-27 | de-supported-rhel9 | — | — |
| ansible-automation-platform-27 | ee-control-plane-rhel9 | — | — |
| ansible-automation-platform-27 | ee-minimal-rhel9 | — | — |
| ansible-automation-platform-27 | ee-supported-rhel9 | — | — |
| ansible-automation-platform-27 | hub-rhel9 | — | — |
| ansible-automation-platform-27 | lightspeed-chatbot-rhel9 | — | — |
CVSS provenance
nvdv4.02.3LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/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:X
vendor_redhat2.3LOW
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GHSA
AIOHTTP: Cookie from subdomain can remove Host-Only Scope from existing cookies
ghsa·2026-10-20
CVE-2026-111749 [LOW] CWE-565 AIOHTTP: Cookie from subdomain can remove Host-Only Scope from existing cookies
AIOHTTP: Cookie from subdomain can remove Host-Only Scope from existing cookies
### Summary
A subdomain can remove the Host-Only flag from an existing cookie to a parent domain.
### Impact
A user accessing untrusted subdomains could see their Host-Only protections stripped from cookies. Given most usecases won't reflect these cookies to a browser, the impact is limited.
Red Hat
aiohttp: aiohttp: Host-Only cookie protection bypass via untrusted subdomain
vendor_redhat·2026-10-19·CVSS 2.3
CVE-2026-111749 [LOW] CWE-346 aiohttp: aiohttp: Host-Only cookie protection bypass via untrusted subdomain
aiohttp: aiohttp: Host-Only cookie protection bypass via untrusted subdomain
A flaw was found in aiohttp. When processing HTTP cookies, a response from an untrusted subdomain can remove the Host-Only attribute from an existing parent-domain cookie. This vulnerability allows an attacker controlling a subdomain to bypass domain isolation protections, potentially exposing sensitive host-specific cookies across broader domain scopes.
Package: exploit-intelligence/vulnerability-analysis-rhel9 (Exploit Intelligence) - Out of support scope
Package: lightspeed-core/lightspeed-stack-rhel9 (Lightspeed Core) - Fix deferred
Package: lightspeed-core/rag-tool-cpu-rhel9 (Lightspeed Core) - Fix deferred
Package: lightspeed-core/rag-tool-cuda-12.9-rhel9 (Lightspeed Core) - Fix deferred
Package: mta/m
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-10-19
Published