CVE-2026-53404VulnerabilityPublished 24 Jun 2026Updated 7 Nov 2026

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

Affects Red HatSource GCVE Database

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Mentioned vulnerabilities

CVE-2026-55955

Authoritative record:CVE-2026-53404· High 7.3

Not known to be exploited · CVSS 7.3 High : upgrade Red Hat tomcat to 8.5.101 soon.

Data as of 13 Nov 2026, 23:54 UTC

CVSS 3.1 base score

7.3High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 8.5.101

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 13 Nov 2026.

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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity 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

Upgrade org.apache.tomcat/tomcat to 8.5.101.

Affected software

Product	Affected	Fixed in
Apache Software FoundationApache Tomcat	Affected >=11.0.0-M1 <=11.0.22 >=10.1.0-M1 <=10.1.55 >=9.0.0.M1 <=9.0.118 >=8.5.0 <=8.5.100	Fixed in–
Mavenorg.apache.tomcat/tomcat`pkg:maven/org.apache.tomcat/tomcat`Other threats	Affected =8.5.0 <8.5.101	Fixed in 8.5.101

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AI-suggested

Red Hat has released updated tomcat10 RPM packages (version 10.1.56-1.hum1) that fix these vulnerabilities. Users should apply these updates to affected Red Hat Hardened Images. For CVE-2026-55955, only deployments using the EncryptionInterceptor for Tribes cluster communication are affected; restricting cluster communication to trusted, isolated networks mitigates risk. Deployments not using this configuration are not affected. No other specific mitigations are indicated.

Description

This update includes the following RPMs: tomcat10: * tomcat10-10.1.56-1.hum1 (noarch) * tomcat10-admin-webapps-10.1.56-1.hum1 (noarch) * tomcat10-common-10.1.56-1.hum1 (noarch) * tomcat10-docs-webapp-10.1.56-1.hum1 (noarch) * tomcat10-el-5.0-api-10.1.56-1.hum1 (noarch) * tomcat10-jsp-3.1-api-10.1.56-1.hum1 (noarch) * tomcat10-lib-10.1.56-1.hum1 (noarch) * tomcat10-servlet-6.0-api-10.1.56-1.hum1 (noarch) * tomcat10-user-instance-10.1.56-1.hum1 (noarch) * tomcat10-webapps-10.1.56-1.hum1 (noarch) * tomcat10-10.1.56-1.hum1.src (src)

Impact

The vulnerabilities fixed by this update could allow unauthorized access or manipulation of data within Tomcat clusters if the EncryptionInterceptor is enabled and the attacker has access to the cluster network. The impact is limited to specific configurations (non-default clustering with EncryptionInterceptor). Red Hat rates the severity as moderate for CVE-2026-55955, with low confidentiality and integrity impact and no availability impact. Other CVEs addressed are not detailed here but are included in the update. There are no known active exploits.

Summary

The advisory updates Red Hat Hardened Images RPMs, including multiple tomcat10 packages to version 10.1.56-1.hum1, addressing several CVEs including CVE-2026-55955. This CVE describes an improper authentication vulnerability in Apache Tomcat's EncryptionInterceptor used for Tribes cluster communication, enabling a replay attack on encrypted cluster messages. Exploitation requires the EncryptionInterceptor to be configured (a non-default setting) and attacker access to the cluster network. Red Hat adjusted the severity to moderate (CVSS 3.1 vector AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N, score 4.2) reflecting the limited attack surface. The advisory includes no explicit patch links but references updated package versions. No known exploits in the wild are reported.

CWE-358Improperly Implemented Security Check for Standard (opens in a new tab)
Base weakness
The product does not implement or incorrectly implements one or more security-relevant checks as specified by the design of a standardized algorithm, protocol, or technique.
CWE-390Detection of Error Condition Without Action (opens in a new tab)
Base weaknessLikelihood of exploit: MediumOWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product detects a specific error, but takes no actions to handle the error.
Implementation
Properly handle each exception. This is the recommended solution. Ensure that all exceptions are handled in such a way that you can be sure of the state of your system at any given moment.
Implementation
If a function returns an error, it is important to either fix the problem and try again, alert the user that an error has happened and let the program continue, or alert the user and close and cleanup the program.
Testing
Subject the product to extensive testing to discover some of the possible instances of where/how errors or return values are not handled. Consider testing techniques such as ad hoc, equivalence partitioning, robustness and fault tolerance, mutation, and fuzzing.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-778Insufficient Logging (opens in a new tab)
Base weaknessLikelihood of exploit: MediumOWASP Top 10 A09:2025: Security Logging & Alerting Failures (opens in a new tab)
When a security-critical event occurs, the product either does not record the event or omits important details about the event when logging it.
Architecture and Design
Use a centralized logging mechanism that supports multiple levels of detail.
Implementation
Ensure that all security-related successes and failures can be logged. When storing data in the cloud (e.g., AWS S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to enable and capture detailed logging information.
Operation
Be sure to set the level of logging appropriately in a production environment. Sufficient data should be logged to enable system administrators to detect attacks, diagnose errors, and recover from attacks.
OWASP Cheat Sheets
Application Logging Vocabulary (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V7.1.3 (opens in a new tab)
V7.2.1 (opens in a new tab)
V7.1.4 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-294Authentication Bypass by Capture-replay (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).
Architecture and Design
Utilize some sequence or time stamping functionality along with a checksum which takes this into account in order to ensure that messages can be parsed only once.
Architecture and Design
Since any attacker who can listen to traffic can see sequence numbers, it is necessary to sign messages with some kind of cryptography to ensure that sequence numbers are not simply doctored along with content.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Session Sidejacking (opens in a new tab)
Kerberoasting (opens in a new tab)
Remote Services with Stolen Credentials (opens in a new tab)
Windows Admin Shares with Stolen Credentials (opens in a new tab)
Reusing Session IDs (aka Session Replay) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-551Incorrect Behavior Order: Authorization Before Parsing and Canonicalization (opens in a new tab)
Base weakness
If a web server does not fully parse requested URLs before it examines them for authorization, it may be possible for an attacker to bypass authorization protection.
Architecture and Design
URL Inputs should be decoded and canonicalized to the application's current internal representation before being validated and processed for authorization. Make sure that your application does not decode the same input twice.
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-305Authentication Bypass by Primary Weakness (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-807Reliance on Untrusted Inputs in a Security Decision (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product uses a protection mechanism that relies on the existence or values of an input, but the input can be modified by an untrusted actor in a way that bypasses the protection mechanism.
Architecture and Design · Attack Surface Reduction
Store state information and sensitive data on the server side only.
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.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
OWASP Cheat Sheets
Secure Design Principles (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, 18:06 UTC

WeaknessesCWE-358, CWE-390, CWE-778 +4

Technical details

References

Community reviews

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