CVE-2026-54279
Description
A flaw was found in aiohttp (before 3.14.1). Host-only cookies saved with CookieJar.save() and later restored with CookieJar.load() lose their host-only flag, so cookies intended for a single host may be sent to subdomains after persistence.
Statement
aiohttp is vulnerable to improper cookie scope handling when persisting and reloading CookieJar data. After save/load, host-only cookies are treated as domain cookies, so session data meant for one host may be sent to subdomains on subsequent requests. Red Hat exposure is in Python asyncio services that bundle aiohttp and persist cookie jars to disk, including AI inference, AAP, and other hybrid platform Python containers.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.3 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | Required | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | None | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability
Technical Impact: Modify Application Data; Execute Unauthorized Code or Commands
Attackers can easily modify cookies, within the browser or by implementing the client-side code outside of the browser. Reliance on cookies without detailed validation and integrity checking can allow attackers to bypass authentication, conduct injection attacks such as SQL injection and cross-site scripting, or otherwise modify inputs in unexpected ways.
Access Control
Technical Impact: Gain Privileges or Assume Identity
It is dangerous to use cookies to set a user's privileges. The cookie can be manipulated to escalate an attacker's privileges to an administrative level.
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