Description
In iTerm2 through 3.6.9, displaying a .txt file can cause code execution via DCS 2000p and OSC 135 data, if the working directory contains a malicious file whose name is valid output from the conductor encoding path, such as a pathname with an initial ace/c+ substring, aka "hypothetical in-band signaling abuse." This occurs because iTerm2 accepts the SSH conductor protocol from terminal output that does not originate from a legitimate conductor session.
Published: 2026-04-18
Score: 6.9 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Local Code Execution
Action: Immediate Patch
AI Analysis

Impact

The vulnerability allows a local attacker to execute arbitrary code when viewing a plain‑text file in iTerm2. It arises because the application accepts SSH conductor escape sequences from terminal output that does not belong to a legitimate conductor session, causing DCS 2000p and OSC 135 sequences to be interpreted. When the working directory contains a specially crafted file whose name matches the expected conductor‑encoded path—such as a name beginning with "ace/c+"—the embedded escape sequences can trigger code execution. This weakness is classified as CWE‑829.

Affected Systems

The affected product is iTerm2 from the vendor iTerm2. Versions up to and including 3.6.9 experience the flaw. All earlier releases prior to 3.6.9 are not noted as affected, and no fix version is given in the CVE data.

Risk and Exploitability

The CVSS base score of 6.9 indicates moderate severity. The EPSS score of less than 1% suggests low exploitation probability, and the vulnerability is not listed in the CISA KEV catalog. Because the attack requires a local user to open a .txt file in a directory that contains a maliciously named file, the vector is local. Exploit conditions include presence of properly encoded filename and the ability to view the file content in iTerm2. The overall risk is moderate for users who routinely open untrusted text files from directories that may contain unknown file names.

Generated by OpenCVE AI on April 18, 2026 at 19:24 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade iTerm2 to the latest release that removes the vulnerable handling of the SSH conductor escape sequences.
  • Until an upgrade is available, avoid opening plain‑text files that are stored in directories containing files with unusual or suspicious names such as those beginning with "ace/c+", and verify file names before viewing.
  • Run iTerm2 with minimal privileges or in a sandboxed environment to limit the impact should exploitation occur.

Generated by OpenCVE AI on April 18, 2026 at 19:24 UTC.

Tracking

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Advisories

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History

Mon, 20 Apr 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Sat, 18 Apr 2026 19:45:00 +0000

Type Values Removed Values Added
Title Local Code Execution via SSH Conductor Escape Sequences in iTerm2

Sat, 18 Apr 2026 06:00:00 +0000

Type Values Removed Values Added
Description In iTerm2 through 3.6.9, displaying a .txt file can cause code execution via DCS 2000p and OSC 135 data, if the working directory contains a malicious file whose name is valid output from the conductor encoding path, such as a pathname with an initial ace/c+ substring, aka "hypothetical in-band signaling abuse." This occurs because iTerm2 accepts the SSH conductor protocol from terminal output that does not originate from a legitimate conductor session.
First Time appeared Iterm2
Iterm2 iterm2
Weaknesses CWE-829
CPEs cpe:2.3:a:iterm2:iterm2:*:*:*:*:*:*:*:*
Vendors & Products Iterm2
Iterm2 iterm2
References
Metrics cvssV3_1

{'score': 6.9, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-04-20T15:52:10.357Z

Reserved: 2026-04-18T05:27:07.778Z

Link: CVE-2026-41253

cve-icon Vulnrichment

Updated: 2026-04-20T15:52:06.515Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-18T06:16:17.427

Modified: 2026-04-20T19:05:30.750

Link: CVE-2026-41253

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-18T19:30:08Z

Weaknesses