CVE-2026-45490: microsoft .net Improper Authorization
CVSS: 7.8v3.1HighModified
AliasesUBUNTU-CVE-2026-45490
Published 09-06-2026Last modified 24-09-2026
Vulnerability summary
CVE-2026-45490 is a high (CVSS 7.8) Improper Authorization vulnerability in microsoft .net. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 35.3% of scored vulnerabilities.
CVSS score
7.8/10
010
High · v3.1 (CVE.org)EPSS score
0.42%
0%100%
Low · +0.04 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 09-06-2026PublishedVulnerability first disclosed.
- 24-09-2026Last modifiedVulnerability information updated.
Description
Improper authorization in .NET allows an authorized attacker to elevate privileges locally.
CVSS metrics
3 scores · 3 sources · 1 versionHigh 7.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.42%
Chance of exploitation in the next 30 days
Percentile
35%
Versus all other CVEs
30-day change
+0.04 pp
From 0.38% on 20-09-2026
20-09-202620-10-2026
EPSS score0.42%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-285Improper AuthorizationThe product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
- CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
- CWE-266Incorrect Privilege AssignmentA product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor.
Affected systems
Microsoft4 products
Ubuntu1 product
- dotnet7All versions (No fix recorded)
2 vendors · 5 products
