Microsoft
Creation of temporary file in directory with insecure permissions in .NET Aspire allows an authorized attacker to elevate privileges locally
At a glance
Low rather than Medium: UK relevance is 40 of 100, little UK-specific signal so far.
Briefing
There is no written leader briefing for this story yet. These questions come from the facts we hold.
Questions to ask IT
- Do we run Microsoft .net, and which versions?
- If it is not yet patched, what mitigation is in place, and will the fix be done by 11 Dec?
Next steps
- Confirm whether this affects systems or suppliers in your estate
Vulnerability facts
Full CVE detail CVE-2026-120778- 7.3 · HighExploitable only with local access and a low-privilege account, but only if a user takes an action, such as opening a file or link. High impact on confidentiality, integrity and availability.CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
- Not listed
- Not linked from the CVE record
No technical write-up beyond these facts and the summary below yet.
Next steps
- Review the advisory against your asset inventory and patch cadence
Summary
- Updated the products listed in the Security Updates table.
Read the original reportMicrosoft Security Update Guide RSS(opens in a new tab)
Products and services involved
- Microsoft .net84% match confidence · CVE-2026-120778
Part of Microsoft security updates address multiple vulnerabilities in ASP.NET Core and .NET
- Missing authorization in Aspire allows an unauthorized attacker to bypass a security feature over a network
- Insertion of sensitive information into log file in Aspire allows an authorized attacker to disclose information locally
- Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network
- Inefficient algorithmic complexity in ASP.NET Core allows an unauthorized attacker to deny service over a network
Pulse
Last change 43m ago · Next recheck 12 Nov 2026, 18:03 UK time
- Story11 Nov 2026, 18:03 UK time · 43m ago
Linked reporting from Microsoft Security Update Guide RSS (vendor psirt).
Read source (Microsoft Security Update Guide RSS)
1 entry so far. The timeline chart appears once this story has more history.
Sources
CVE-2026-120778 Aspire Elevation of Privilege Vulnerability
How we know
Statements extracted from sources. Higher confidence means stronger corroboration.
- ClaimedHeadline60% confidence
Creation of temporary file in directory with insecure permissions in.NET Aspire allows an authorised attacker to elevate privileges locally
- ProbableSummary fact75% confidence
Updated the products listed in the Security Updates table.
- ConfirmedCVE identifier95% confidence
Event involves CVE-2026-120778