CVE-2026-73070: Vim stack buffer overflow in socket server

CVE-2026-73070 · Severity: medium · CVSS 5.5 · Published 2026-08-11

Vim is a widely-used command-line text editor that can operate as a socket server for remote connections. Prior to version 9.2.0842, the socket server accepts an unbounded number of client connections, which can overflow internal data structures and allow a local attacker to corrupt memory or crash the server. This could disrupt users relying on Vim's server functionality or enable privilege escalation on shared systems.

Technologies: Vim. Vendors: Vim.

Quick answers

Is CVE-2026-73070 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-73070 being exploited in the wild.
How severe is CVE-2026-73070?
Medium severity, with a CVSS score of 5.5, published 11 August 2026.
Which products and versions are affected?
Vim prior to 9.2.0842.
Is there a fix for CVE-2026-73070?
A patch was published on 2026-07-23: Fix released in version 9.2.0842 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-73070 attacked?
It is attacked with local access or from the adjacent network.
Am I affected by CVE-2026-73070?
Check whether you run Vim at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a stack buffer overflow in Vim's socket server backend (src/socketserver.c). The socketserver_accept() function accepts unlimited client connections without bounds checking, causing file descriptors to overflow fixed-size fd_set structures in src/channel.c and pollfd arrays in src/os_unix.c. A local process with the ability to connect to the server socket can trigger this overflow to corrupt stack memory or terminate the Vim server. The attack requires local network or socket access and no authentication. The fix, implemented in version 9.2.0842, caps the number of accepted socket connections to prevent descriptor overflow.

Affected products

  • Vim Vim prior to 9.2.0842

Timeline

  • 2026-08-11: disclosed: CVE-2026-73070 published
  • 2026-07-23: patched: Fix released in version 9.2.0842

References

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