CVE-2026-123784

CVSS 8.5 (high) · published 2026-11-06

Fluxbox through 1.3.7 contains an OS command injection vulnerability in RootTheme::reconfigTheme() that allows attackers to execute commands via crafted style background values. Attackers can embed shell metacharacters in background pixmap paths, random directories, or gradient texture text, which are concatenated unescaped into an fbsetbg command run via $SHELL -c when the style loads.

Weakness: CWE-78

Source: NVD CVE-2026-123784

References

• https://github.com/fluxbox/fluxbox
• https://github.com/fluxbox/fluxbox/blob/Release-1_3_7/src/RootTheme.cc#L192-L264
• https://github.com/fluxbox/fluxbox/commit/270bfbc28573037c9b8458488d193b219e33889f
• https://github.com/fluxbox/fluxbox/pull/89
• https://www.vulncheck.com/advisories/fluxbox-through-1.3.7-os-command-injection-via-style-background-values

Check your software

Connect an AI agent to the Fixlane MCP server or ask the Telegram bot to check what you have installed against incidents with a verified fixed version.