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Fencer Vulns
medium 6.2

CVE-2026-45491 json

.NET Tampering Vulnerability

published 2026-06-09 5 mo ago modified 2026-09-24 45 d ago also BIT-dotnet-2026-45491 , BIT-dotnet-sdk-2026-45491 , EUVD-2026-35675 , GHSA-7q4v-2mr6-5gpx

cvss
6.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits
0
none known

Summary

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

Patch / fix

  • nuget Microsoft.NETCore.App.Runtime.linux-x64 8.0.28, 9.0.17, 10.0.9
  • nuget Microsoft.NETCore.App.Runtime.win-x64 8.0.28, 9.0.17, 10.0.9
  • nuget Microsoft.NETCore.App.Runtime.osx-arm64 8.0.28, 9.0.17, 10.0.9
  • bitnami dotnet 8.0.28, 9.0.17, 10.0.9
  • bitnami dotnet-sdk 8.0.28, 9.0.17, 10.0.9
  • Microsoft .NET 10.0 10.0.9
  • Microsoft .NET 8.0 8.0.28
  • Microsoft .NET 9.0 9.0.17
  • dotnet8 Ubuntu 22.04 LTS 8.0.128-8.0.28-0ubuntu1~22.04.1
  • dotnet8 Ubuntu 24.04 LTS 8.0.128-8.0.28-0ubuntu1~24.04.1
  • dotnet8 Ubuntu 25.10 8.0.128-8.0.28-0ubuntu1~25.10.1
  • dotnet9 Ubuntu 25.10 9.0.118-9.0.17-0ubuntu1~25.10.1
  • dotnet10 Ubuntu 24.04 LTS 10.0.109-10.0.9-0ubuntu1~24.04.1
  • dotnet10 Ubuntu 25.10 10.0.109-10.0.9-0ubuntu1~25.10.1
  • dotnet10 Ubuntu 26.10 10.0.109-10.0.9-0ubuntu1
  • dotnet10 Ubuntu 26.04 LTS 10.0.109-10.0.9-0ubuntu1~26.04.1

ubuntu advisories UBUNTU-CVE-2026-45491

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • dotnet8.0 hummingbird 1 8.0.128-1.hum1
  • dotnet-sdk-8.0 hummingbird 1 8.0.128-1.hum1
  • dotnet-sdk-dbg-8.0 hummingbird 1 8.0.128-1.hum1
  • dotnet-templates-8.0 hummingbird 1 8.0.128-1.hum1
  • dotnet-sdk-8.0-source-built-artifacts hummingbird 1 8.0.128-1.hum1
  • dotnet10.0 hummingbird 1 10.0.109-1.hum1
  • dotnet-sdk-10.0 hummingbird 1 10.0.109-1.hum1
  • dotnet-sdk-aot-10.0 hummingbird 1 10.0.109-1.hum1

red hat advisories RHSA-2026:28051RHSA-2026:28227RHSA-2026:28011RHSA-2026:28009RHSA-2026:28007RHSA-2026:26994

  • dotnet-sdk-8.0 AlmaLinux 9 8.0.128-1.el9_8
  • dotnet-hostfxr-8.0 AlmaLinux 9 8.0.28-1.el9_8
  • dotnet-runtime-8.0 AlmaLinux 9 8.0.28-1.el9_8
  • dotnet-sdk-dbg-8.0 AlmaLinux 9 8.0.128-1.el9_8
  • dotnet-templates-8.0 AlmaLinux 9 8.0.128-1.el9_8
  • aspnetcore-runtime-8.0 AlmaLinux 9 8.0.28-1.el9_8
  • dotnet-runtime-dbg-8.0 AlmaLinux 9 8.0.28-1.el9_8
  • dotnet-apphost-pack-8.0 AlmaLinux 9 8.0.28-1.el9_8

almalinux advisories ALSA-2026:25220ALSA-2026:25221ALSA-2026:25222ALSA-2026:25110ALSA-2026:25111ALSA-2026:25112

  • dotnet8.0 Rocky Linux 10 8.0.128-1.el10_2
  • dotnet9.0 Rocky Linux 10 9.0.118-1.el10_2
  • dotnet10.0 Rocky Linux 10 10.0.109-1.el10_2
  • dotnet8.0 Rocky Linux 9 8.0.128-1.el9_8
  • dotnet9.0 Rocky Linux 9 9.0.118-1.el9_8
  • dotnet10.0 Rocky Linux 9 10.0.109-1.el9_8
  • dotnet8.0 Rocky Linux 8 8.0.128-1.el8_10
  • dotnet9.0 Rocky Linux 8 9.0.118-1.el8_10

rocky linux advisories RLSA-2026:25111RLSA-2026:25112RLSA-2026:25115RLSA-2026:25220RLSA-2026:25221RLSA-2026:25222

  • dotnet8-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 8.0.28-r0
  • dotnet9-runtime Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 9.0.17-r0
  • dotnet10-runtime Alpine 3.24, Alpine 3.23 10.0.9-r0

alpine advisories ALPINE-CVE-2026-45491

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-45491 updated cvss 6.2

dotnet: .NET: Local file tampering via link following vulnerability

  • Red Hat CodeReady Linux Builder EUS (v.9.6) dotnet-sdk-8.0-source-built-artifacts 8.0.128-1.el9_6, dotnet-sdk-9.0-source-built-artifacts 9.0.118-1.el9_6
    fixed: vendor fix RHSA-2026:28011
  • Red Hat Enterprise Linux AppStream (v. 8) dotnet 10.0.109-1.el8_10, dotnet8.0 8.0.128-1.el8_10, dotnet9.0 9.0.118-1.el8_10, dotnet-host 10.0.9-1.el8_10, dotnet10.0 10.0.109-1.el8_10, dotnet-sdk-8.0 8.0.128-1.el8_10, +35 more
    fixed: vendor fix RHSA-2026:25114
  • Red Hat Enterprise Linux AppStream (v. 9) dotnet8.0 8.0.128-1.el9_8, dotnet9.0 9.0.118-1.el9_8, dotnet-host 10.0.9-1.el9_8, dotnet10.0 10.0.109-1.el9_8, dotnet-sdk-8.0 8.0.128-1.el9_8, dotnet-sdk-9.0 9.0.118-1.el9_8, +34 more
    fixed: vendor fix RHSA-2026:25222
  • Red Hat Enterprise Linux AppStream (v. 10) dotnet8.0 8.0.128-1.el10_2, dotnet9.0 9.0.118-1.el10_2, dotnet-host 10.0.9-1.el10_2, dotnet10.0 10.0.109-1.el10_2, dotnet-sdk-8.0 8.0.128-1.el10_2, dotnet-sdk-9.0 9.0.118-1.el10_2, +34 more
    fixed: vendor fix RHSA-2026:25115
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) dotnet8.0 8.0.128-1.el9_4, dotnet-host 8.0.28-1.el9_4, dotnet-sdk-8.0 8.0.128-1.el9_4, dotnet-hostfxr-8.0 8.0.28-1.el9_4, dotnet-runtime-8.0 8.0.28-1.el9_4, dotnet-sdk-dbg-8.0 8.0.128-1.el9_4, +8 more
    fixed: vendor fix RHSA-2026:28227
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) dotnet8.0 8.0.128-1.el10_0, dotnet9.0 9.0.118-1.el10_0, dotnet-host 9.0.17-1.el10_0, dotnet-sdk-8.0 8.0.128-1.el10_0, dotnet-sdk-9.0 9.0.118-1.el10_0, dotnet-hostfxr-8.0 8.0.28-1.el10_0, +21 more
    fixed: vendor fix RHSA-2026:28007
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) dotnet8.0 8.0.128-1.el9_6, dotnet9.0 9.0.118-1.el9_6, dotnet-host 9.0.17-1.el9_6, dotnet-sdk-8.0 8.0.128-1.el9_6, dotnet-sdk-9.0 9.0.118-1.el9_6, dotnet-hostfxr-8.0 8.0.28-1.el9_6, +21 more
    fixed: vendor fix RHSA-2026:28011
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dotnet-sdk-8.0-source-built-artifacts 8.0.128-1.el9_8, dotnet-sdk-9.0-source-built-artifacts 9.0.118-1.el9_8, dotnet-sdk-10.0-source-built-artifacts 10.0.109-1.el9_8
    fixed: vendor fix RHSA-2026:25222
show 5 more
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dotnet-sdk-8.0-source-built-artifacts 8.0.128-1.el10_2, dotnet-sdk-9.0-source-built-artifacts 9.0.118-1.el10_2, dotnet-sdk-10.0-source-built-artifacts 10.0.109-1.el10_2
    fixed: vendor fix RHSA-2026:25115
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) dotnet-sdk-8.0-source-built-artifacts 8.0.128-1.el10_0, dotnet-sdk-9.0-source-built-artifacts 9.0.118-1.el10_0
    fixed: vendor fix RHSA-2026:28007
  • Red Hat Enterprise Linux CRB (v. 8) dotnet-sdk-8.0-source-built-artifacts 8.0.128-1.el8_10, dotnet-sdk-9.0-source-built-artifacts 9.0.118-1.el8_10, dotnet-sdk-10.0-source-built-artifacts 10.0.109-1.el8_10
    fixed: vendor fix RHSA-2026:25114
  • Red Hat Hardened Images dotnet8.0 8.0.128-1.hum1, dotnet9.0 9.0.117-1.hum1, dotnet10.0 10.0.109-1.hum1, dotnet-sdk-8.0 8.0.128-1.hum1, dotnet-sdk-10.0 10.0.109-1.hum1, dotnet-sdk-dbg-8.0 8.0.128-1.hum1, +6 more
    fixed: vendor fix RHSA-2026:26638
  • Red Hat Hardened Images dotnet-host 10.0.9-1.hum1, dotnet-sdk-9.0 9.0.117-1.hum1, dotnet-hostfxr-8.0 8.0.28-1.hum1, dotnet-hostfxr-9.0 9.0.16-1.hum1, dotnet-runtime-8.0 8.0.28-1.hum1, dotnet-runtime-9.0 9.0.16-1.hum1, +25 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C
GitHub 3.1 6.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
CNA 3.1 6.2 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
OSV 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
nuget Microsoft.NETCore.App.Runtime.linux-x64
>=8.0.0, <8.0.28
>=9.0.0, <9.0.17
>=10.0.0, <10.0.9
8.0.28
9.0.17
10.0.9
nuget Microsoft.NETCore.App.Runtime.win-x64
>=8.0.0, <8.0.28
>=9.0.0, <9.0.17
>=10.0.0, <10.0.9
8.0.28
9.0.17
10.0.9
nuget Microsoft.NETCore.App.Runtime.osx-arm64
>=8.0.0, <8.0.28
>=9.0.0, <9.0.17
>=10.0.0, <10.0.9
8.0.28
9.0.17
10.0.9
bitnami dotnet
>=8.0.0, <8.0.28
>=9.0.0, <9.0.17
>=10.0.0, <10.0.9
8.0.28
9.0.17
10.0.9
bitnami dotnet-sdk
>=8.0.0, <8.0.28
>=9.0.0, <9.0.17
>=10.0.0, <10.0.9
8.0.28
9.0.17
10.0.9

Affected products

  • Microsoft .NET 10.0
  • Microsoft .NET 8.0
  • Microsoft .NET 9.0

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.