Claude Code CVE-2026-39861:sandbox escape via symlink
47 points by Armor1AI 20 hours ago | 7 comments
  • Imustaskforhelp 19 hours ago |
    Interesting that the submission just before this is about:

    Anthropic response to 1-click pwn: Shouldn't have clicked 'ok': https://news.ycombinator.com/item?id=48057836

    This makes me think a bit more about this CVE more too.

    Anthropic lately has been really trying to burn any/every good will that they have it seems. Also a bit ironical about how the most dangerous model (Mythos) which can find CVE in other projects wasn't able to find this CVE within the claude-code project itself.

  • az226 15 hours ago |
    And yet Mythos couldn’t find it. Whomp whomp
    • amluto 8 hours ago |
      Mythos might be good at finding holes in an actual defined security boundary. But trying to audit Claude Code would be like trying to find the holes in Swiss cheese. Of course they’re there!
    • philipwhiuk 8 hours ago |
      Maybe if they'd submitted each file twice instead of only once /s
    • quinncom 7 hours ago |
      Probably it did, but just thought, “I’m saving this one just for me”
    • perching_aix 3 hours ago |
      I honestly wonder if they run it against it. Like sure, it'd be very, very obvious for them to. But it'd be so quintessentially human not to.

      The shoemaker's children go barefoot and all...

  • bredren 6 hours ago |
    I identified this in August last year but it was specifically excluded by Anthropic's Vulnerability Disclosure Program Policy at the time.

    You can still see the exclusion on HackerOne: https://hackerone.com/anthropic-vdp/policy_scopes

       Out of Scope:

    Abusing intended functionality of Claude CLI
    Using aliased commands, symlinks or other environment-specific settings to bypass permission prompts
    Local storage of Claude Code credentials, configuration and logs
    Symlinks have been very important to manage skills from disparate sources and managing multiple CLIs.

    Codex did not originally support symlink'd skills but added it in response to user requests on Jan 9th.