Quick answers
- Is CVE-2026-52859 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-52859 being exploited in the wild.
- How severe is CVE-2026-52859?
- Informational severity, with a CVSS score of 6.9, published 11 June 2026.
- Which products and versions are affected?
- Vim < 9.2.0565.
- Is there a fix for CVE-2026-52859?
- A patch was published on 2026-05-30: Patch 9.2.0565 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-52859 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-52859?
- 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
An out-of-bounds read vulnerability exists in Vim's `update_snapshot()` function within `src/terminal.c`. The function iterates through a cell's `chars[]` array without an upper bound, relying solely on a NUL terminator. When a terminal cell is filled with the maximum allowed characters (one base character and five combining marks), the underlying `libvterm` library returns the array without a NUL terminator. This causes the loop to read past the six-element array and append out-of-bounds data to a fixed-size buffer. An attacker can trigger this by running a program inside a `:terminal` window that outputs a specific byte sequence, resulting in an application crash (DoS). The vulnerability is fixed in version 9.2.0565 by adding a loop guard.
Affected products
- Vim Vim < 9.2.0565
Timeline
- 2026-05-30: patched: Patch 9.2.0565 released
- 2026-05-30: advisory: GitHub Security Advisory published
- 2026-06-11: disclosed: CVE published to NVD