CVE-2023-35391 | ASP.NET Core SignalR and Visual Studio Information Disclosure Vulnerability

ASP.NET Core SignalR and Visual Studio Information Disclosure Vulnerability

Published: 2023-08-08 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-35391 is rated Moderate Risk (50.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.94%). Review affected assets and schedule remediation.

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-2023-35391

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 3.29% 1.94% -1.35%
2 2026-06-12 2.59% 3.29% +0.70%
3 2026-06-04 — 2.59% —

Full EPSS history (29 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-35391

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:H/I:N/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.5 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-35391

GitHub Security Advisory for CVE-2023-35391

GHSA-j8rm-cm55-qqj6 · Severity: high · Ecosystem: nuget — .NET Information Disclosure Vulnerability

OS Trackers for CVE-2023-35391

vendor priority summary link
alpine high CVE-2023-35391: 4 source package rows (dotnet6-build, dotnet6-runtime, dotnet7-build, dotnet7-runtime); 14 state rows across 4 repos (3.18-community, 3.19-community, 3.20-community, edge-community); fixed 14, open 0. https://security.alpinelinux.org/vuln/CVE-2023-35391
redhat medium — https://access.redhat.com/security/cve/CVE-2023-35391
ubuntu medium CVE-2023-35391 medium priority: Ubuntu including 2 source packages (dotnet6, dotnet7), 14 status rows across 7 suites (bionic, focal, jammy, lunar, trusty, upstream, xenial): DNE 8, not-affected 4, needs-triage 2. https://ubuntu.com/security/CVE-2023-35391

Affected software / configurations for CVE-2023-35391

Vendor Product Version Raw CPE
microsoft .net >= 6.0.0, < 6.0.21 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft .net >= 7.0.0, < 7.0.10 cpe:2.3:a:microsoft:.net:*:*:*:*:*:*:*:*
microsoft asp.net_core >= 2.1, < 2.1.40 cpe:2.3:a:microsoft:asp.net_core:*:*:*:*:*:*:*:*
microsoft visual_studio_2022 >= 17.2.0, < 17.2.18 cpe:2.3:a:microsoft:visual_studio_2022:*:*:*:*:*:*:*:*
microsoft visual_studio_2022 >= 17.4.0, < 17.4.10 cpe:2.3:a:microsoft:visual_studio_2022:*:*:*:*:*:*:*:*
microsoft visual_studio_2022 >= 17.6.0, < 17.6.6 cpe:2.3:a:microsoft:visual_studio_2022:*:*:*:*:*:*:*:*

References for CVE-2023-35391

cvelogic Threat Intelligence