Patch tracker / CVE reference / CVE-2025-55315

CVE-2025-55315

CVE-2025-55315 is a critical severity Microsoft vulnerability with a CVSS score of 9.9. Its EPSS score puts the probability of exploitation in the next 30 days at 66%. Microsoft has shipped the fix: deploy one of the 2 updates below from the Microsoft Update Catalog, and see where this CVE sits against the rest on the patch tracker.

Risk summary

Critical

9.9

CVSS

66%

EPSS, 30 days

Critical

Severity

Not in the CISA KEV catalog. EPSS exploit probability 66%. CVSS 9.9 (Critical).

This CVE is among the top 25% of tracked Microsoft CVEs by EPSS exploit probability.

Senserva AI Opinion for CVE-2025-55315

A Critical Severity (CVSS 9.9) security feature bypass in ASP.NET Core affecting versions 2.3, 8.0, and 9.0, with an EPSS of 66% that is remarkably high for a bug not yet in the CISA KEV catalog. Framework flaws like this are sneaky operationally: fixing them is not one patch but a package update and redeploy for every application built on the vulnerable runtime. Bypass bugs in the request-handling layer can let attackers smuggle requests past security controls the application thinks are enforced.

Do this: Inventory every ASP.NET Core application, update the runtime and packages, and redeploy, starting with internet-facing apps.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2025-55315

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I am an IT admin assessing a vulnerability. Facts for CVE-2025-55315 (source: https://senserva.com/cve/CVE-2025-55315.html, data from MSRC, CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2025-55315: Critical severity Microsoft vulnerability, CVSS 9.9
- EPSS 30-day exploitation probability: 66%
- Actively exploited (CISA KEV): no
- Fixed by: KB5068331, KB5068332
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) What to patch or mitigate first. 4) How to check whether my devices are exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch this cycle

Not confirmed exploited yet, but the 30-day exploit probability is high (EPSS 66%).

Fixed by KB5068331 and 1 more (by build, listed below). Download from the Microsoft Update Catalog, or deploy via Windows Update, Intune, or WSUS.

Do this now: Patch in this maintenance window; do not let it slip to the next one.

Official patch(es) for CVE-2025-55315

High priority: EPSS puts the odds of near-term exploitation high. In Intune or Defender, confirm whether the fixing updates KB5068331, KB5068332 are installed across the affected products. Senserva does this automatically across your tenant and flags every missing patch.

Apply the Microsoft security updates below to fix CVE-2025-55315. Each KB page carries the Microsoft Update Catalog download, Microsoft's known issues for the update, a copy-paste PowerShell check for whether it is installed, and the Senserva AI read.

KB5068331 KB5068332

Scope and sources

Affected products

Fixed by the same updates

CVE-2025-55247 CVE-2025-55248

Authoritative references

Official CVE record (cve.org)NVD detail Microsoft MSRC FIRST.org EPSS

Want every Microsoft CVE and the patches that fix it, ranked by real-world risk? See the Microsoft Patch Tracker.