HighVulnerability

CVE-2026-11326: OpenAI Atlas cross-site scripting exposes privileged browser APIs

Source: NVD(opens in a new tab)
Identifier: CVE-2026-11326
Published: June 4, 2026
Record updated: October 9, 2026

Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.2%

Summary

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 reach these functions, allowing access to browser history and the ability to open or close tabs. The weakness is classified as CWE-284, Improper Access Control.

Mitigation

OpenAI Atlas 1.2025.288.15 narrows access to these APIs to *.chatgpt.com; users should upgrade to 1.2025.288.15 or later.

Details

Scores and exploitation

EPSS: 0.2%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 4, 2026.
Disclosure date: June 4, 2026

Weaknesses and techniques

Weakness (CWE): CWE-284

Affected

Vendors: OpenAI

Classification

Attack type: Other
Attack sophistication: Moderate
AI component targeted: Plugin
Impact: Confidentiality,
Integrity
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-11326

First tracked: June 5, 2026 at 02:08 AM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 85% (self-assessed)

Summary

Mitigation

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