mediumAgent ThreatTool Misuse

Oh My Posh Terminal Escape Sequence Injection via Unsanitized Git Metadata

First seen Aug 13, 2026 · Updated Aug 13, 2026 · CVSS 6.1

terminal-injectionescape-sequencesoh-my-poshgit-metadataprompt-rendererCVE-2026-73506ANSI-injectionclipboard-hijackSurface: Human InterfacePropagation: Single Hop

This CVE describes a terminal escape sequence injection vulnerability in the Oh My Posh shell prompt renderer, not an AI agent-specific prompt injection despite the matched keyword. Attacker-controlled Git metadata (commit messages, author names, repo URLs) and directory names could contain unsanitized control characters that manipulate the terminal, spoof the display, or overwrite the clipboard when a victim's shell prompt renders that data. This is a legitimate but conventional software vulnerability with no direct relevance to AI agent architectures, LLM prompt injection, or inter-agent protocols.

Technical Analysis

The vulnerability resides in write(s rune) within src/terminal/writer.go, which renders shell prompt segments including current directory names and Git metadata (Commit.Subject, Commit.Author.Name, Commit.Author.Email, RawUpstreamURL) without stripping C0/C1 control characters such as ESC, BEL, CSI, and OSC sequences. An attacker who controls a Git repository (via commit metadata, branch names, or remote URLs) that a victim clones or navigates into can embed terminal escape sequences that execute when Oh My Posh renders the prompt. This allows clipboard overwrite (OSC 52), prompt/screen spoofing, window title manipulation, or terminal disruption purely through terminal control-sequence interpretation by the user's terminal emulator, not through any AI model or agent reasoning process. The entry point is untrusted repository data flowing into a human-facing rendering pipeline; there is no LLM, tool-calling agent, or inter-agent protocol involved.

Affected Systems

Oh My Posh

Detection Signatures

  • Prompt or terminal output containing raw ESC (0x1B), BEL (0x07), CSI (ESC [), or OSC (ESC ]) sequences originating from git log, git remote, or directory name fields
  • Unexpected clipboard content changes correlated with shell prompt rendering or `cd` into untrusted repositories
  • Git commit subjects/author fields containing non-printable control characters when inspected with `cat -v` or `od -c`
  • Sudden window title changes not initiated by the user
  • Oh My Posh versions prior to 29.35.1

Remediation Steps

  1. 1

    Upgrade Oh My Posh

    Update to version 29.35.1 or later, which sanitizes C0/C1 control characters from Git metadata and directory names before rendering.

  2. 2

    Sanitize untrusted Git metadata

    If maintaining a fork or custom prompt renderer, strip or escape ESC/BEL/CSI/OSC control sequences from any data sourced from repository content before terminal output.

  3. 3

    Audit repositories before navigation

    Exercise caution when cloning or cd'ing into untrusted repositories, especially those with unusual commit messages, author fields, or remote URLs.

  4. 4

    Use terminal emulator protections

    Enable terminal emulator settings that restrict or confirm risky OSC sequences such as clipboard write (OSC 52) and window title changes.

CVE / Advisory IDs

CVE-2026-73506

Industries Most Exposed

Software DevelopmentTechnologyDevOps/SRE tooling users across all sectors

Sources

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