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Fencer Vulns
medium 4.7

CVE-2026-54162 json

Ember: Unneutralised terminal escape/control sequences from Caddy logs injected into the operator's TUI

published 2026-08-20 2 mo ago modified 2026-10-29 10 d ago also GHSA-x3g7-qrwc-f6c5 , GO-2026-6270 , EUVD-2026-112411

cvss
4.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

Ember is a real-time terminal dashboard for Caddy servers with FrankenPHP support. Prior to 1.4.2, interactive TUI row formatters pass Caddy access-log fields, particularly the request URI, through the `fitCellLeft` render helper without neutralizing terminal escape or control sequences. An unauthenticated remote client can place ANSI, OSC, or CSI control bytes in an ordinary HTTP request target. Caddy JSON-escapes those bytes, `ParseLogLine` decodes them back into raw controls, and the formatters concatenate them into `View()` output reaching `os.Stdout`. When the operator views the default `Logs` tab, the terminal interprets these sequences, allowing monitoring-dashboard spoofing, clipboard hijacking through `OSC 52`, and window-title spoofing through `OSC 0/2`. This works even with a loopback-only log listener because the input arrives through normal Caddy access logs. `Certificates` and `Routes` share secondary unneutralized render sinks. The `--json`, `--once`, and daemon `--expose` modes are unaffected because they do not render an interactive terminal. Consequences depend on the terminal emulator and usually require further operator action to escalate; this is not general-purpose remote code execution. This issue is fixed in version 1.4.2.

Patch / fix

  • go github.com/alexandre-daubois/ember 1.4.2
  • govulncheck-vulndb SLES for SAP applications 16.0, SLES 16.0 0.0.20260827T195228-160000.1.1

suse advisories SUSE-SU-2026:23625-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260827T195228-160000.1.1

opensuse advisories openSUSE-SU-2026:21761-1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
10 d ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
GitHub 3.1 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
go github.com/alexandre-daubois/ember
<1.4.2
1.4.2

Affected products

  • alexandre-daubois ember

Classification

Weakness
  • CWE-150 Improper Neutralization of Escape, Meta, or Control Sequences

References

Sources

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.