CVE-2026-104420 Vulnerability Analysis & Exploit Details

CVE-2026-104420
Vulnerability Scoring

5.3
/10
Significant Risk

Security assessments indicate that CVE-2026-104420 presents a notable risk, potentially requiring prompt mitigation.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: None
    No privileges are required for exploitation.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2026-104420 Details

Status: Deferred

Last updated: 🕒 06 Oct 2026, 03:17 UTC
Originally published on: 🕛 02 Oct 2026, 12:17 UTC

Time between publication and last update: 3 days

CVSS Release: version 3

CVSS3 Source

disclosure@vulncheck.com

CVSS3 Type

Secondary

CVSS3 Vector

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

CVE-2026-104420 Vulnerability Summary

CVE-2026-104420: Zebra before 6.3.0 contains a protection mechanism failure that allows unauthenticated peers to evade misbehavior scoring by supplying invalid gossiped blocks. The inbound cleanup step wrongly downcasts RouterError to VerifyBlockError and discards the score, so attackers can repeatedly force block download and Equihash verification without being banned.

Assessing the Risk of CVE-2026-104420

Access Complexity Graph

The exploitability of CVE-2026-104420 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2026-104420

With low attack complexity and no required privileges, CVE-2026-104420 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2026-104420, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2026-104420, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2026-104420 has no significant impact on data confidentiality.
  • Integrity: None
    CVE-2026-104420 poses no threat to data integrity.
  • Availability: Low
    CVE-2026-104420 may slightly degrade system performance without fully affecting service availability.

CVE-2026-104420 References

External References

CWE Common Weakness Enumeration

CWE-704

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