CVE-2026-45491 | .NET Tampering Vulnerability

Improper link resolution before file access ('link following') in .NET allows an unauthorized attacker to perform tampering locally.

Published: 2026-06-09 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-45491 is rated Low Risk (32.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.30%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-45491

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.09% 0.30% +0.21%
2 2026-06-10 — 0.09% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-45491

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.2 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.5 3.6 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2026-45491

GitHub Security Advisory for CVE-2026-45491

GHSA-7q4v-2mr6-5gpx · Severity: medium · Ecosystem: nuget — Microsoft Security Advisory CVE-2026-45491 – .NET Tampering Vulnerability

OS Trackers for CVE-2026-45491

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2026-45491
ubuntu medium CVE-2026-45491 medium priority: Ubuntu including 5 source packages (dotnet10, dotnet6, dotnet7, dotnet8, dotnet9), 45 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 31, needed 7, needs-triage 5, deferred 1, ignored 1. https://ubuntu.com/security/CVE-2026-45491

Affected software / configurations for CVE-2026-45491

Vendor Product Version Raw CPE
microsoft .net >= 8.0.0, < 8.0.28 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net >= 9.0.0, < 9.0.17 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net >= 10.0.0, < 10.0.9 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*

References for CVE-2026-45491

cvelogic Threat Intelligence