CVE-2026-123785

MEDIUM 5.5

Fluxbox through 1.3.7 Infinite Loop via Menu::updateMenu() Style Geometry

CVSS Score

5.5

EPSS Score

0.0%

EPSS Percentile

0th

Fluxbox through 1.3.7 contains an infinite loop vulnerability in Menu::updateMenu() in src/FbTk/Menu.cc that allows attackers to hang the window manager via crafted style geometry values. Attackers can supply a style with an oversized unbounded menu.titleHeight so the column loop never terminates, causing sustained CPU use and denial of service at startup.

CWE	CWE-835
Vendor	fluxbox
Product	fluxbox
Published	Nov 6, 2026
Last Updated	Nov 6, 2026

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CVSS v3 Breakdown

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

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected Versions

fluxbox / fluxbox

0 ≤ 1.3.7

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/fluxbox/fluxbox/pull/90 github.com: https://github.com/fluxbox/fluxbox github.com: https://github.com/fluxbox/fluxbox/blob/Release-1_3_7/src/FbTk/Menu.cc#L433-L448 vulncheck.com: https://www.vulncheck.com/advisories/fluxbox-through-1.3.7-infinite-loop-via-menu-updatemenu-style-geometry

Credits

Igor Marcel