CVE-2026-58649
published 2026-09-08CVE-2026-58649: Origin validation error in .NET allows an unauthorized attacker to disclose information over a network.
PriorityP335medium6.5CVSS 3.1
AVNACLPRNUIRSUCHINAN
EPSS
0.36%
29.4th percentile
Origin validation error in .NET allows an unauthorized attacker to disclose information over a network.
Affected
23 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | microsoft_visual_studio_2022_version_17.14 | >= 17.14.0 < 17.14.40 | 17.14.40 |
| microsoft | microsoft_visual_studio_2026_version_18.9 | >= 18.9.0 < 18.9.3 | 18.9.3 |
| microsoft | net | — | — |
| microsoft | net | — | — |
| microsoft | net | — | — |
| microsoft | net | — | — |
| microsoft | net | — | — |
| microsoft | net | — | — |
| microsoft | net | — | — |
| microsoft | net_10.0 | >= 10.0.0 < 10.0.111, 10.0.400 | 10.0.111, 10.0.400 |
| microsoft | net_11.0 | >= 11.0.0 < 11.0 RC1 | 11.0 RC1 |
| microsoft | net_8.0 | >= 8.0.0 < 8.0.130, 8.0.424 | 8.0.130, 8.0.424 |
| microsoft | net_9.0 | >= 9.0.0 < 9.0.120, 9.0.317 | 9.0.120, 9.0.317 |
| microsoft | net_sdk | >= 10.0.100 < 10.0.111 | 10.0.111 |
| microsoft | net_sdk | >= 10.0.200 < 10.0.400 | 10.0.400 |
| microsoft | net_sdk | >= 8.0.100 < 8.0.130 | 8.0.130 |
| microsoft | net_sdk | >= 8.0.200 < 8.0.424 | 8.0.424 |
| microsoft | net_sdk | >= 9.0.100 < 9.0.120 | 9.0.120 |
| microsoft | net_sdk | >= 9.0.200 < 9.0.317 | 9.0.317 |
| microsoft | visual_studio_2022 | >= 17.14.0 < 17.14.40 | 17.14.40 |
| microsoft | visual_studio_2026 | >= 18.9.0 < 18.9.3 | 18.9.3 |
| ubuntu | dotnet10 | — | — |
| ubuntu | dotnet8 | — | — |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
vendor_redhat6.5MEDIUM
vendor_ubuntu6.5MEDIUM
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Ubuntu
.NET vulnerabilities
vendor_ubuntu·2026-09-10·CVSS 6.5
CVE-2026-58649 [MEDIUM] .NET vulnerabilities
Title: .NET vulnerabilities
Summary: Several security issues were fixed in .NET.
Weeraphat Srisutham discovered that the .NET watch BrowserRefreshServer did
not properly validate cross-origin WebSocket connections. An attacker could
possibly use this issue to expose sensitive information. (CVE-2026-58649)
Rajesh Chada discovered that the .NET watch AspireServerService improperly
exposed information through the use of certain arguments. An attacker could
possibly use this issue to elevate privileges and execute arbitrary code.
(CVE-2026-69806)
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
dotnet10.0: dotnet9.0: dotnet8.0: .NET Information Disclosure Vulnerability
vendor_redhat·2026-09-08·CVSS 6.5
CVE-2026-58649 [MEDIUM] CWE-346 dotnet10.0: dotnet9.0: dotnet8.0: .NET Information Disclosure Vulnerability
dotnet10.0: dotnet9.0: dotnet8.0: .NET Information Disclosure Vulnerability
dotnet watch BrowserRefreshServer does not adequately validate cross-origin WebSocket origins, potentially allowing IL and PDB information disclosure.
Package: dotnet10.0 (Red Hat Enterprise Linux 10) - Affected
Package: dotnet8.0 (Red Hat Enterprise Linux 10) - Affected
Package: dotnet9.0 (Red Hat Enterprise Linux 10) - Affected
Package: dotnet10.0 (Red Hat Enterprise Linux 8) - Affected
Package: dotnet8.0 (Red Hat Enterprise Linux 8) - Affected
Package: dotnet9.0 (Red Hat Enterprise Linux 8) - Affected
Package: dotnet10.0 (Red Hat Enterprise Linux 9) - Affected
Package: dotnet8.0 (Red Hat Enterprise Linux 9) - Affected
Package: dotnet9.0 (Red Hat Enterprise Linux 9) - Affected
Package: dotnet10.0 (Red
GHSA
Origin validation error in .NET allows an unauthorized attacker to disclose information over a network.
ghsa_unreviewed·2026-09-08
CVE-2026-58649 [MEDIUM] CWE-346 Origin validation error in .NET allows an unauthorized attacker to disclose information over a network.
Origin validation error in .NET allows an unauthorized attacker to disclose information over a network.
No detection rules found.
No public exploits indexed.
Sans Isc
September 2026 Microsoft Patch Tuesday, (Tue, Sep 8th)
blogs_sans_isc·2026-09-08·CVSS 7.8
CVE-2026-81963 [HIGH] September 2026 Microsoft Patch Tuesday, (Tue, Sep 8th)
September 2026 Microsoft Patch Tuesday
Published: 2026-09-08. Last Updated: 2026-09-08 19:20:30 UTC
by Johannes Ullrich (Version: 1)
0 comment(s)
This month, Microsoft released patches for a record-breaking 973 vulnerabilities, including 113 rated critical. It is by far the largest Patch Tuesday to date, well ahead of the previous high of 664 set in July 2026. Two vulnerabilities are listed as exploited in the wild, while none were publicly disclosed before Patch Tuesday. Notable fixes include Windows privilege escalation and critical RCEs in Skype for Business, MSMQ and RRAS.
A few vulnerabilities worth mentioning:
Windows Update Stack Elevation of Privilege Vulnerability (CVE-2026-81963)
Microsoft reports that CVE-2026-81963 is being exploited, though it was not publicly disclosed b
Rapid7
Patch Tuesday - September 2026
blogs_rapid7·2026-09-08·CVSS 7.8
CVE-2026-85880 [HIGH] Patch Tuesday - September 2026
Microsoft is publishing 974 own-product vulnerabilities on September 2026 Patch Tuesday , including 723 vulnerabilities in Windows. Along with Microsoft fixes for 25 non-Microsoft CVEs, that brings the total number of vulnerabilities on the table today to 999. Whether this is the biggest Patch Tuesday ever depends on how we count, but this is by far the most CVEs that Microsoft has ever published in a single day. As Rapid7 noted last month, there is no reason to suppose that Patch Tuesday will ever return to the lower volumes we saw prior to 2026. Microsoft is aware of exploitation in the wild for two of the vulnerabilities published today.
## Windows ALPC: zero-day EoP
The eternal game of elevation of privilege whack-a-mole between Microsoft and attackers continues. This month, the batt
Bugzilla
CVE-2026-58649 dotnet8.0: .NET Information Disclosure Vulnerability [fedora-all]
bugzilla·2026-09-09·CVSS 6.5
CVE-2026-58649 [MEDIUM] CVE-2026-58649 dotnet8.0: .NET Information Disclosure Vulnerability [fedora-all]
CVE-2026-58649 dotnet8.0: .NET Information Disclosure Vulnerability [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
dotnet watch BrowserRefreshServer does not adequately validate cross-origin WebSocket origins, potentially allowing IL and PDB information disclosure.
CNA: microsoft
CNA impact: Information Disclosure
CWE: CWE-346
Platforms: all
Architectures: all
CVSS 3.1: 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N)
Affected packages:
- dotnet-sdk (release 10.0): 10.0.400 - 10.0.400; fixed 10.0.401 [dotnet@ae39133]
- dotnet-sdk (release 9.0): 9.0.300 - 9.0.317; fixed 9.0.318 [sdk@d78666e]
- dotn
Bugzilla
CVE-2026-58649 dotnet10.0: .NET Information Disclosure Vulnerability [fedora-all]
bugzilla·2026-09-09·CVSS 6.5
CVE-2026-58649 [MEDIUM] CVE-2026-58649 dotnet10.0: .NET Information Disclosure Vulnerability [fedora-all]
CVE-2026-58649 dotnet10.0: .NET Information Disclosure Vulnerability [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
dotnet watch BrowserRefreshServer does not adequately validate cross-origin WebSocket origins, potentially allowing IL and PDB information disclosure.
CNA: microsoft
CNA impact: Information Disclosure
CWE: CWE-346
Platforms: all
Architectures: all
CVSS 3.1: 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N)
Affected packages:
- dotnet-sdk (release 10.0): 10.0.400 - 10.0.400; fixed 10.0.401 [dotnet@ae39133]
- dotnet-sdk (release 9.0): 9.0.300 - 9.0.317; fixed 9.0.318 [sdk@d78666e]
- dot
Bugzilla
CVE-2026-58649 dotnet9.0: .NET Information Disclosure Vulnerability [fedora-all]
bugzilla·2026-09-09·CVSS 6.5
CVE-2026-58649 [MEDIUM] CVE-2026-58649 dotnet9.0: .NET Information Disclosure Vulnerability [fedora-all]
CVE-2026-58649 dotnet9.0: .NET Information Disclosure Vulnerability [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
dotnet watch BrowserRefreshServer does not adequately validate cross-origin WebSocket origins, potentially allowing IL and PDB information disclosure.
CNA: microsoft
CNA impact: Information Disclosure
CWE: CWE-346
Platforms: all
Architectures: all
CVSS 3.1: 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N)
Affected packages:
- dotnet-sdk (release 10.0): 10.0.400 - 10.0.400; fixed 10.0.401 [dotnet@ae39133]
- dotnet-sdk (release 9.0): 9.0.300 - 9.0.317; fixed 9.0.318 [sdk@d78666e]
- dotn
Bugzilla
CVE-2026-58649 dotnet10.0: dotnet9.0: dotnet8.0: .NET Information Disclosure Vulnerability
bugzilla·2026-09-04·CVSS 6.5
CVE-2026-58649 [MEDIUM] CVE-2026-58649 dotnet10.0: dotnet9.0: dotnet8.0: .NET Information Disclosure Vulnerability
CVE-2026-58649 dotnet10.0: dotnet9.0: dotnet8.0: .NET Information Disclosure Vulnerability
dotnet watch BrowserRefreshServer does not adequately validate cross-origin WebSocket origins, potentially allowing IL and PDB information disclosure.
CNA: microsoft
CNA impact: Information Disclosure
CWE: CWE-346
Platforms: all
Architectures: all
CVSS 3.1: 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N)
Affected packages:
- dotnet-sdk (release 10.0): 10.0.400 - 10.0.400; fixed 10.0.401 [dotnet@ae39133]
- dotnet-sdk (release 9.0): 9.0.300 - 9.0.317; fixed 9.0.318 [sdk@d78666e]
- dotnet-sdk (release 10.0): 10.0.100 - 10.0.111; fixed 10.0.112 [dotnet@882ef16]
- dotnet-sdk (release 8.0): 8.0.100 - 8.0.130; fixed 8.0.131 [sdk@de67b09]
- dotnet-sdk (release 8.0): 8.0.400 - 8.0.424; fixed 8.0.425 [sd
2026-09-08
Published