CVE-2026-123784 json
Fluxbox through 1.3.7 OS Command Injection via Style Background Values
published 2026-11-06 2 d ago modified 2026-11-06 2 d ago also EUVD-2026-118302
- cvss
- 7.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 53%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- github.com/fluxbox/fluxbox@270bfbc commit
- github.com/fluxbox/fluxbox#89 pull request
Exploit prediction
0.71% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.5 | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 8.5 | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
Affected products
- fluxbox fluxbox
Classification
- Weakness
-
- CWE-78 Improper Neutralization of Special Elements used in an OS Command
References
-
github.com
/fluxbox/fluxbox/pull/89
issue-tracking, patch
-
github.com
/fluxbox/fluxbox/commit/270bfbc28573037c9b8458488d193b219e33889f
patch
-
github.com
/fluxbox/fluxbox
product
-
github.com
/fluxbox/fluxbox/blob/Release-1_3_7/src/RootTheme.cc#L192-L264
technical-description
-
vulncheck.com
/advisories/fluxbox-through-1.3.7-os-command-injection-via-style-background-values
third-party-advisory
Sources
- CVE List CVE-2026-123784
- NVD CVE-2026-123784
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.