CVE-2026-54279: CWE-665: Improper Initialization in aio-libs aiohttp
### Summary Host-only cookies that are saved with ``CookieJar.save()`` and then restored later with ``CookieJar.load()`` lose their host-only status. ### Impact Host-only cookies that have been loaded from disk may get sent to subdomains that previously should have been disallowed. ----- Patch: https://github.com/aio-libs/aiohttp/commit/a329a7aacad5284f087af36103aff778746da0f2
AI Analysis
Technical Summary
The vulnerability in aiohttp (CVE-2026-54279) involves improper initialization related to host-only cookies. Specifically, when host-only cookies are saved using CookieJar.save() and later restored with CookieJar.load(), they lose their host-only attribute in versions before 3.14.1. This could affect cookie handling behavior in applications using aiohttp. The issue is addressed in version 3.14.1.
Potential Impact
The improper handling of host-only cookies may lead to cookies being treated as less restrictive than intended, potentially allowing cookies to be sent in contexts where they should not be. However, the CVSS score of 1.3 and the low severity rating indicate the impact is minimal and does not involve privilege escalation, authentication bypass, or direct compromise.
Mitigation Recommendations
Upgrade aiohttp to version 3.14.1 or later, where this vulnerability is fixed. No other mitigation or temporary workaround is indicated.
CVE-2026-54279: CWE-665: Improper Initialization in aio-libs aiohttp
Description
### Summary Host-only cookies that are saved with ``CookieJar.save()`` and then restored later with ``CookieJar.load()`` lose their host-only status. ### Impact Host-only cookies that have been loaded from disk may get sent to subdomains that previously should have been disallowed. ----- Patch: https://github.com/aio-libs/aiohttp/commit/a329a7aacad5284f087af36103aff778746da0f2
CVSS v4.0
Score 1.3low
Affected software
aio-libs
aiohttp
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in aiohttp (CVE-2026-54279) involves improper initialization related to host-only cookies. Specifically, when host-only cookies are saved using CookieJar.save() and later restored with CookieJar.load(), they lose their host-only attribute in versions before 3.14.1. This could affect cookie handling behavior in applications using aiohttp. The issue is addressed in version 3.14.1.
Potential Impact
The improper handling of host-only cookies may lead to cookies being treated as less restrictive than intended, potentially allowing cookies to be sent in contexts where they should not be. However, the CVSS score of 1.3 and the low severity rating indicate the impact is minimal and does not involve privilege escalation, authentication bypass, or direct compromise.
Mitigation Recommendations
Upgrade aiohttp to version 3.14.1 or later, where this vulnerability is fixed. No other mitigation or temporary workaround is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-12T17:13:32.280Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a39735ceed863c81e396293
Added to database: 06/22/2026, 17:39:40 UTC
Last enriched: 06/22/2026, 17:55:23 UTC
Last updated: 09/19/2026, 22:01:35 UTC
Views: 120
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