Quick answers
- Is CVE-2026-33019 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-33019 being exploited in the wild.
- How severe is CVE-2026-33019?
- High severity, with a CVSS score of 7.1, published 14 April 2026.
- Which products and versions are affected?
- Saitoha Libsixel <= 1.8.7.
- Is there a fix for CVE-2026-33019?
- A patch was published on 2026-04-14: Fixed in version 1.8.7-r1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-33019 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-33019?
- Check whether you run Saitoha Libsixel 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 integer overflow exists in the `sixel_encoder_do_clip()` function of libsixel. When the `--crop` option is used with a coordinate value near INT_MAX (e.g., 2,147,483,647), the bounds check `clip_w + clip_x > src_width` overflows to a negative value, bypassing the safety guard. This unclamped coordinate is eventually passed to `memmove()`, which attempts to read from a source pointer calculated far beyond the allocated image buffer. This results in an out-of-bounds heap read, causing a reliable application crash and potential information disclosure. The vulnerability is exploitable if a user is convinced to run the `img2sixel` utility with a malicious crop argument against a valid image.
Affected products
- saitoha libsixel <= 1.8.7
Timeline
- 2026-04-14: disclosed
- 2026-04-14: patched: Fixed in version 1.8.7-r1
- 2026-04-14: advisory