CVE-2025-55315

Published Oct 14, 2025

Last updated 6 days ago

CVSS critical 9.9
ASP.NET Core

Overview

AI description

Automated description summarized from trusted sources.

CVE-2025-55315 is a security vulnerability affecting ASP.NET Core, specifically the Kestrel web server. It stems from an inconsistent interpretation of HTTP requests, leading to HTTP request smuggling. This vulnerability allows an unauthenticated attacker to smuggle HTTP requests. Successful exploitation of CVE-2025-55315 could allow attackers to bypass security controls, potentially exposing sensitive information like user credentials, modifying files on the server, or even causing a server crash. The vulnerability can be exploited to perform actions such as user spoofing, server-side request forgery, bypassing cross-site request forgery (CSRF) protections, and injection attacks. To mitigate this vulnerability, Microsoft has released security updates for various versions of ASP.NET Core.

Description
Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized attacker to bypass a security feature over a network.
Source
secure@microsoft.com
NVD status
Analyzed
Products
asp.net_core, visual_studio_2022

Risk scores

CVSS 3.1

Type
Primary
Base score
9.9
Impact score
6
Exploitability score
3.1
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
Severity
CRITICAL

Weaknesses

secure@microsoft.com
CWE-444

Social media

Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.

Hype score

38

  1. Se ha confirmado la vulnerabilidad CVE-2025-55315 con severidad CVSS 9.9, la cual afecta a https://t.co/Ez9h48qhXc Core (versiones 6.0.0 ≤ v ≤ 6.0.36, 8.0.0 ≤ v ≤ 8.0.20, 9.0.0 ≤ v ≤ 9.0.9) y al componente Kestrel.Core ≤ 2.3.6. La falla permite manipular encabezados

    @tpx_Security

    22 Oct 2025

    6 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  2. Update 7 Hotfix Wir haben einen Hotfix veröffentlicht, der Probleme mit der Syslog-Protokollierung behebt und die neuesten Microsoft https://t.co/2prAbvD7ay Core-Sicherheitspatches (CVE-2025-55315) enthält. Mehr hier: https://t.co/m7krcmqway #3CX #Update7 #Sicherheitsupdate

    @3CX_DACH

    22 Oct 2025

    7 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  3. Is this real or a joke CVE-2025-55315 ? https://t.co/9fUTjaTjuF Core is vulnerable to http request smuggling !!!! And why is no one talking about it? https://t.co/o7darxqsL5 https://t.co/b9nZASxnHu

    @h4x0r_dz

    21 Oct 2025

    25851 Impressions

    51 Retweets

    375 Likes

    227 Bookmarks

    6 Replies

    0 Quotes

  4. Waspada Dev! CVE-2025-55315 (CVSS 9.9) di https://t.co/k8SOwsic6l Core bikin HTTP smuggling gampang banget. 489K+ layanan kebuka lebar via Hunter! PoC Python-nya udah siap test. Udah patch belum nih? Share pengalamanmu! #CyberSec #Vuln [Attach image: PoC Code Snippet] Quote

    @BJORKANISM_REAL

    21 Oct 2025

    134 Impressions

    0 Retweets

    2 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  5. 🔥Criminal IP Cyber News – 10월 21일🔥​ 🔓 #마이크로소프트, https://t.co/FMzPJeULxP Core 최고 심각도 취약점 패치​ HTTP 요청 스머글링 버그(CVE-2025-55315)로 인증 공격자가 다른 사용자 계정 탈취·서버 파일 변경 가능​

    @CriminalIP_KR

    21 Oct 2025

    100 Impressions

    0 Retweets

    0 Likes

    1 Bookmark

    0 Replies

    0 Quotes

  6. 🚨🚨CVE-2025-55315 (CVSS: 9.9) : https://t.co/qsOziXctBq Kestrel HTTP Request and Response Smuggling https://t.co/qsOziXctBq Kestrel has inconsistencies in HTTP parsing that allow an authenticated attacker to bypass network defenses via HTTP request/response smuggling. 🔥

    @zoomeye_team

    21 Oct 2025

    8501 Impressions

    38 Retweets

    145 Likes

    72 Bookmarks

    1 Reply

    1 Quote

  7. ‘Highest Ever’ Severity Score Assigned by Microsoft - CVE-2025-55315 - https://t.co/XAUfsbAcbx

    @SecurityWeek

    20 Oct 2025

    4812 Impressions

    9 Retweets

    31 Likes

    10 Bookmarks

    0 Replies

    1 Quote

  8. click bait headline but still valid #ITSecurity ‘Highest Ever’ Severity Score Assigned by Microsoft to https://t.co/RTXe4LfXc9 Core Vulnerability CVE-2025-55315 is an HTTP request smuggling bug leading to information leaks, file content tampering, and server crashes.

    @seaarepea

    19 Oct 2025

    79 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  9. Abbreviated Reproduction of CVE-2025-55315 (Critical 9.9 https://t.co/pQViwsfEm8 Kestrel HTTP Request and Response Smuggling) https://t.co/fTUCjLnspm https://t.co/6FCCeZAFCA

    @freedomhack101

    18 Oct 2025

    166 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

  10. 🚨 The Kestrel Conundrum: Deconstructing the Critical #CVE-2025-55315 Request Smuggling Vulnerability https://t.co/u5NtYnerIN Educational Purposes!

    @UndercodeUpdate

    18 Oct 2025

    116 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  11. 🚨 Vulnerabilidad crítica en https://t.co/ANjMDS9MqA Core web server ⚠️ CVE-2025-55315 https://t.co/WjRMgHovTq

    @elhackernet

    18 Oct 2025

    2372 Impressions

    4 Retweets

    15 Likes

    2 Bookmarks

    0 Replies

    0 Quotes

  12. 🚨 مایکروسافت خطرناک‌ترین باگ تاریخ #ASP_NET_Core را پچ کرد! باگ CVE-2025-55315 در وب‌سرور Kestrel اجازه می‌داد مهاجمان درخواست‌های HTTP را مخفیانه تزریق کنند و به داده‌

    @vulnerbyte

    18 Oct 2025

    96 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

  13. Microsoft patches critical https://t.co/PGRGNLeuSX Core flaw CVE-2025-55315 affecting Kestrel server that risks credential theft and server breaches. Updates advised for .NET 8, 2.3, and related apps. #ASPNetCore #MicrosoftPatch #USA https://t.co/IbHpQvocOC

    @TweetThreatNews

    17 Oct 2025

    98 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  14. مایکروسافت این هفته آسیب‌پذیری با بالاترین درجه شدت تاریخ ASP .NET Core را ترمیم کرد. این باگ قاچاق درخواست HTTP (CVE-2025-55315) در وب سرور Kestrel ASP .NET Core کشف شد و به مهاجم

    @Teeegra

    17 Oct 2025

    1455 Impressions

    0 Retweets

    26 Likes

    2 Bookmarks

    0 Replies

    0 Quotes

  15. Microsoft assigns highest ever severity score (9.9) to an HTTP request smuggling flaw in https://t.co/PGRGNLeuSX Core's Kestrel server (CVE-2025-55315). Patches released to prevent session hijacking and data leaks. #ASPNetCore #KestrelServer #USA https://t.co/B47dqzS2yP

    @TweetThreatNews

    17 Oct 2025

    22 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  16. CVE-2025-55315, a 9.9 HTTP smuggling vulnerability in dotnet Kestrel webserver disclosed this week, caught my attention this morning due to lack of information, so I put together a very limited analysis of it. https://t.co/9y5CH2qezK More to be done here for those interested!

    @7urb01

    16 Oct 2025

    6072 Impressions

    14 Retweets

    84 Likes

    38 Bookmarks

    0 Replies

    0 Quotes

  17. 🚨 https://t.co/wYRWE2eQNj Core HTTP BYPASS — CVE-2025-55315! Patch https://t.co/iYrMleF7I8.Runtime / Kestrel NOW. If you can’t patch immediately, limit public exposure (WAF / isolate services), monitor HTTP/3/request anomalies, and check logs. 📷 https://t.co/nu4bsU2KIQ

    @vulert_official

    15 Oct 2025

    30 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

Configurations

References

Sources include official advisories and independent security research.