Fluxbox up to 1.3.7 Menu Update src/FbTk/Menu.cc Menu::updateMenu infinite loop

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.1$0-$5k1.67

Summaryinfo

A vulnerability labeled as problematic has been found in Fluxbox up to 1.3.7. The impacted element is the function Menu::updateMenu of the file src/FbTk/Menu.cc of the component Menu Update. Such manipulation leads to infinite loop. This vulnerability is documented as CVE-2026-123785. The attack needs to be performed locally. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Fluxbox up to 1.3.7. Affected by this issue is the function Menu::updateMenu of the file src/FbTk/Menu.cc of the component Menu Update. The manipulation with an unknown input leads to a infinite loop vulnerability. Using CWE to declare the problem leads to CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. Impacted is availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-123785 since 11/06/2026. The exploitation is known to be easy. Local access is required to approach this attack. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.1
VulDB Meta Temp Score: 4.1

VulDB Base Score: 2.8
VulDB Temp Score: 2.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

11/06/2026 Advisory disclosed
11/06/2026 +0 days CVE reserved
11/06/2026 +0 days VulDB entry created
11/06/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Not defined

CNA: VulnCheck
CVE: CVE-2026-123785 (🔒)

GCVE (CVE): GCVE-0-2026-123785
GCVE (VulDB): GCVE-100-431966

Entryinfo

Created: 11/06/2026 16:35
Changes: 11/06/2026 16:35 (75)
Complete: 🔍
Cache ID: 216::103

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