CVE-2026-33800: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-cxfq-ph57-rvh2
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CVSS 6.5
CWE-606
Published
Advisory Summary

CVE-2026-33800 is a HIGH (CVSS 6.5) security vulnerability vulnerability (CWE-606: Unchecked Input for Loop Condition) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-33800 at a Glance

CVE Identifier CVE-2026-33800
GHSA Identifier GHSA-cxfq-ph57-rvh2
Severity HIGH
CVSS v3.1 Base Score 6.5
CWE Classification CWE-606: Unchecked Input for Loop Condition
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Adjacent (AV:A)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-33800

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-33800, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-606: Unchecked Input for Loop Condition, where the product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

An Unchecked Input for Loop Condition vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).Micro-BFD session flaps generate respective up/down events which are queued by PFEMAN for processing. Especially in a Virtual-Chassis (VC) scenario with locality‑bias configured, processing takes a significant amount of time for each event. If these sessions keep flapping, new events are constantly added, and in turn PFEMAN never completes processing these events. This results in the PFEMAN watchdog timer expiring, which causes the FPC to crash and restart, representing a complete service outage. This issue only affects MX series FPCs up to and including MPC9. It does not affect MPC10/11, LC4800/9600 and MX304. This issue affects Junos OS on MX Series: * all versions before 23.2R2-S7, * 23.4 versions before 23.4R2-S8, * 24.2 versions before 24.2R2-S4, * 24.4 versions before 24.4R2-S3, * 25.2 versions before 25.2R2.

References

NVD — CVE-2026-33800 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33800
supportportal.juniper.net/jsa110075 WEB
https://supportportal.juniper.net/JSA110075

Frequently Asked Questions

What is CVE-2026-33800?
CVE-2026-33800 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-606: Unchecked Input for Loop Condition.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-33800?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-33800?
CVE-2026-33800 has a CVSS v3.1 base score of 6.5 (HIGH) with vector string CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-33800?
CVE-2026-33800 is classified under CWE-606: Unchecked Input for Loop Condition (The product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.).
How can I check Maven dependencies for CVE-2026-33800?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cxfq-ph57-rvh2",
  "modified" : "2026-07-20T15:31:35Z",
  "published" : "2026-07-09T21:31:21Z",
  "aliases" : [ "CVE-2026-33800" ],
  "details" : "An Unchecked Input for Loop Condition vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).Micro-BFD session flaps generate respective up/down events which are queued by PFEMAN for processing. Especially in a Virtual-Chassis (VC) scenario with locality‑bias configured, processing takes a significant amount of time for each event. If these sessions keep flapping, new events are constantly added, and in turn PFEMAN never completes processing these events. This results in the PFEMAN watchdog timer expiring, which causes the FPC to crash and restart, representing a complete service outage.\n\n\nThis issue only affects MX series FPCs up to and including MPC9. It does not affect MPC10/11, LC4800/9600 and MX304.\n\nThis issue affects Junos OS on MX Series:\n\n\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S8,\n  *  24.2 versions before 24.2R2-S4,\n  *  24.4 versions before 24.4R2-S3,\n  *  25.2 versions before 25.2R2.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:X/RE:M/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33800"
  }, {
    "type" : "WEB",
    "url" : "https://supportportal.juniper.net/JSA110075"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-606" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-09T21:16:55Z"
  }
}