Azure OpenAI: Microsoft publishes a CVSS 9.8 missing authentication CVE

01What happened

Microsoft disclosed CVE-2026-119990 on 10 November 2026, naming Azure OpenAI, its hosted service for OpenAI models. Microsoft is the assigning authority, publishes no technical write-up beyond the record, and credits no outside researcher. CISA's enrichment of the record lists exploitation as none, automatable as yes, and the technical impact as total.

02How it works

The weakness is classed as CWE-306, missing authentication for a critical function, and the stated effect is that an unauthorized attacker can elevate privileges over a network. The published vector, AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, describes a remote caller who needs no privileges and no user interaction, with high impact on confidentiality, integrity and availability. Which function lacked the check is not described anywhere in the record.

03Who is affected

Azure OpenAI is the only product named. The record lists the affected range as service builds from 1.0.0 up to, but not including, hyena-infra-build-official/20260923.14, and tags the product as an exclusively hosted service, so no customer-installable patch exists.

04What to do

No patching work follows for customers, because the fix sits in a Microsoft-operated service build and the record's remediation level reads official fix. Teams that keep a register of AI service CVEs should file this one as an inventory note, and ask Microsoft through support if they need the exposure window for an audit.

Sources 3 links, all fetched

1. 1msrc.microsoft.comMicrosoft Advisory
2. 2github.comGitHub Advisory
3. 3cveawg.mitre.orgCVE Record