Vulnerability · Published Jun 5, 2026 · Assigned by OAI

CVE-2026-11326

Medium 6.0

In plain English

A medium-severity improper access control in OpenAI Atlas from OpenAI. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).

Severity (CVSS 4.0)6.0Medium

Exploit odds (30 days)0.2%top 88.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

OpenAI Atlas before 1.2025.288.15 exposed privileged browser APIs to web content on *.openai.com origins. A cross-site scripting vulnerability in forum.openai.com could be used to access these functions, allowing access to browser history information and the ability to open or close tabs. OpenAI Atlas 1.2025.288.15 narrows access to these APIs to *.chatgpt.com; users should upgrade to 1.2025.288.15 or later.

Affected products (as reported)

Vendor	Product	Versions
OpenAI	OpenAI Atlas	0 – before 1.2025.288.15

Weakness: CWE-284 · Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/AU:N/V:D/RE:L/U:Green

References

Pwning OpenAI Atlas Through Exposed Browser Internals technical-description