CVE-2025-26646VulnerabilityPublished 21 Apr 2026Updated 5 Oct 2026

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Affects Red HatSource GCVE Database

Mentioned vulnerabilities

CVE-2025-55315

Not known to be exploited.

Data as of 25 Oct 2026, 19:02 UTC

Severity

High

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 1.2% chance of exploitation in 30 days – higher than 69% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Red Hat Product Security Red Hat	Affected Red Hat Red Hat Hardened Images aarch64 dotnet9-0-main@aarch64 aspnetcore-runtime-9.0-0:9.0.15-1.hum1@aarch64	Fixed in–

AI-suggested

The vendor advisory states that mitigation for the HTTP request smuggling vulnerability is either not available or does not meet Red Hat's criteria for ease of use, deployment, applicability, or stability. Users are advised to refer to the provided updated RPM packages and Red Hat's official update channels for applying this update. For unsupported product streams, no fixes will be provided, and upgrading to supported versions is recommended. Customers with Red Hat Technical Account Managers can seek direct guidance.

Description

This update includes the following RPMs: dotnet9.0: * aspnetcore-runtime-9.0-9.0.15-1.hum1 (aarch64, x86_64) * aspnetcore-runtime-dbg-9.0-9.0.15-1.hum1 (aarch64, x86_64) * aspnetcore-targeting-pack-9.0-9.0.15-1.hum1 (aarch64, x86_64) * dotnet-apphost-pack-9.0-9.0.15-1.hum1 (aarch64, x86_64) * dotnet-hostfxr-9.0-9.0.15-1.hum1 (aarch64, x86_64) * dotnet-runtime-9.0-9.0.15-1.hum1 (aarch64, x86_64) * dotnet-runtime-dbg-9.0-9.0.15-1.hum1 (aarch64, x86_64) * dotnet-sdk-9.0-9.0.116-1.hum1 (aarch64, x86_64) * dotnet-sdk-9.0-source-built-artifacts-9.0.116-1.hum1 (aarch64, x86_64) * dotnet-sdk-aot-9.0-9.0.116-1.hum1 (aarch64, x86_64) * dotnet-sdk-dbg-9.0-9.0.116-1.hum1 (aarch64, x86_64) * dotnet-targeting-pack-9.0-9.0.15-1.hum1 (aarch64, x86_64) * dotnet-templates-9.0-9.0.116-1.hum1 (aarch64, x86_64) * netstandard-targeting-pack-2.1-9.0.116-1.hum1 (aarch64, x86_64) * dotnet9.0-9.0.116-1.hum1.src (src)

Impact

The primary impact involves potential bypass of security controls via HTTP request smuggling in ASP.NET Core, allowing an authorized network attacker to manipulate request boundaries. This can lead to exposure or unauthorized actions on request data. The advisory indicates high confidentiality impact and low integrity impact for this vulnerability. Other vulnerabilities covered by the advisory are not detailed in terms of impact. No known exploits in the wild are reported. The advisory also notes that some affected product streams (.NET 6.0 for certain Red Hat platforms) are no longer supported and will not receive fixes.

Summary

The advisory from Red Hat Product Security covers a security update for Red Hat Hardened Images RPMs, including numerous dotnet9.0-related packages for aarch64 and x86_64. It addresses multiple CVEs, including CVE-2025-55315, which is a flaw in ASP.NET Core's HTTP request parsing that can be exploited by an authorized network attacker to perform HTTP request smuggling. This vulnerability can lead to bypassing security controls and unintended forwarding of request data. The advisory states that .NET 6.0 for RHEL-8, RHEL-9, and RHIVOS has reached end of life and will not receive fixes. Mitigations for the HTTP request smuggling issue are either unavailable or insufficient per Red Hat's criteria. The advisory does not explicitly confirm patch availability for the vulnerabilities but provides updated RPM packages as part of the update. Multiple related CVEs are referenced, but no CVSS scores are provided. Red Hat remains the authoritative source for impact and remediation status.

CWE-290Authentication Bypass by Spoofing (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
OWASP Cheat Sheets
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V3.5.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
Attack patterns
Creating a Rogue Certification Authority Certificate (opens in a new tab)
Web Services API Signature Forgery Leveraging Hash Function Extension Weakness (opens in a new tab)
Signature Spoof (opens in a new tab)
Signature Spoofing by Misrepresentation (opens in a new tab)
Session Credential Falsification through Prediction (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-377Insecure Temporary File (opens in a new tab)
Class weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
Creating and using insecure temporary files can leave application and system data vulnerable to attack.
OWASP Cheat Sheets
Authorization (opens in a new tab)
Attack patterns
Explore for Predictable Temporary File Names (opens in a new tab)
Screen Temporary Files for Sensitive Information (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-319Cleartext Transmission of Sensitive Information (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.
Architecture and Design
Before transmitting, encrypt the data using reliable, confidentiality-protecting cryptographic protocols.
Implementation
When using web applications with SSL, use SSL for the entire session from login to logout, not just for the initial login page.
Implementation
When designing hardware platforms, ensure that approved encryption algorithms (such as those recommended by NIST) protect paths from security critical data to trusted user applications.
OWASP Cheat Sheets
Transport Layer Protection (opens in a new tab)
TLS Cipher String (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.1 (opens in a new tab)
V9.2.2 (opens in a new tab)
V1.9.1 (opens in a new tab)
Attack patterns
Session Sidejacking (opens in a new tab)
Harvesting Information via API Event Monitoring (opens in a new tab)
Signature Spoofing by Mixing Signed and Unsigned Content (opens in a new tab)
Sniff Application Code (opens in a new tab)
Interception (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') (opens in a new tab)
Base weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
Implementation
Use a web server that employs a strict HTTP parsing procedure, such as Apache.
Implementation
Use only SSL communication.
Implementation
Terminate the client session after each request.
OWASP Cheat Sheets
REST Assessment (opens in a new tab)
REST Security (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V13.2.5 (opens in a new tab)
Attack patterns
HTTP Response Smuggling (opens in a new tab)
HTTP Request Smuggling (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-776Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion') (opens in a new tab)
Base weaknessLikelihood of exploit: MediumOWASP Top 10 A02:2025: Security Misconfiguration (opens in a new tab)
The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
Operation
If possible, prohibit the use of DTDs or use an XML parser that limits the expansion of recursive DTD entities.
Implementation
Before parsing XML files with associated DTDs, scan for recursive entity declarations and do not continue parsing potentially explosive content.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
Exponential Data Expansion (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-138Improper Neutralization of Special Elements (opens in a new tab)
Class weaknessOWASP Top 10 A03:2021: Injection (opens in a new tab)
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as control elements or syntactic markers when they are sent to a downstream component.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Implementation
Developers should anticipate that special elements (e.g. delimiters, symbols) will be injected into input vectors of their product. One defense is to create an allowlist (e.g. a regular expression) that defines valid input according to the requirements specifications.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Implementation
Use and specify an appropriate output encoding to ensure that the special elements are well-defined. A normal byte sequence in one encoding could be a special element in another.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V5.2.2 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
HTTP Request Splitting (opens in a new tab)
Command Delimiters (opens in a new tab)
HTTP Response Splitting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Aug 2026, 18:09 UTC

WeaknessesCWE-290, CWE-377, CWE-319 +4

Technical details

References

Community reviews

Related threats