CVE-2026-88837

Description

BusyBox httpd treats yescrypt ($y$) password hashes as plaintext during Basic Authentication, inverting the authentication check.

Statement

Fedora 44 uses yescrypt ($y$) as the default password hashing algorithm, so any Fedora system administrator who configures BusyBox httpd with inline password hashes will produce vulnerable configurations by default. However, BusyBox httpd is not used as a web server on Fedora in any standard deployment.

Mitigation

Do not use BusyBox httpd for password-protected resources. If it must be used, configure authentication with SHA-512 ($6$) hashes, which are correctly detected. Upstream should update the hash detection logic to recognize the $y$ prefix.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score6.5N/A6.5
Attack VectorNetworkN/ANetwork
Attack ComplexityHighN/AHigh
Privileges RequiredNoneN/ANone
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityHighN/AHigh
Integrity ImpactLowN/ALow
Availability ImpactNoneN/ANone

Vector

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

cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Understanding the Weakness (CWE)

Access Control

Technical Impact: Bypass Protection Mechanism

Acknowledgements

Red Hat would like to thank Shubham Raj (Causal Security) for reporting this issue.

Frequently Asked Questions

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