CVE-2026-53459: Bambuddy's authentication fails open on database errors, allowing unauthenticated access to all endpoints

Severity: critical (CVSS 9.3 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-15 · updated 2026-09-29
Weakness: CWE-636

Description

Bambuddy is a self-hosted print archive and management system for Bambu Lab 3D printers. Starting in version 0.1.6 and prior to version 0.2.4.4, a fail-open in the authentication code allows any attacker to bypass authentication by flooding a public endpoint to exhaust resources causing database access to fail, granting unauthenticated access to all protected endpoints. Version 0.2.4.4 patches the issue.

Affected products

maziggy bambuddy: from 0.1.6, < 0.2.4.4

References

https://github.com/maziggy/bambuddy/blob/449502cc9fc1cec04f06d31512420eac729fd032/backend/app/core/auth.py#L473-L483
https://github.com/maziggy/bambuddy/blob/449502cc9fc1cec04f06d31512420eac729fd032/backend/app/main.py#L5314-L5316
https://github.com/maziggy/bambuddy/blob/main/CHANGELOG.md
https://github.com/maziggy/bambuddy/commit/845ad39b19bf99afeea571c6bae09695777e1460
https://github.com/maziggy/bambuddy/releases/tag/v0.2.4.4
https://github.com/maziggy/bambuddy/security/advisories/GHSA-6mf4-q26m-47pv

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