What is CVE-2021-46700?

CVE-2021-46700 is a medium-severity vulnerability in Saitoha Libsixel, classified under Double Free. CVSS score: 6.5/10. Published 2022-02-19.

How severe is CVE-2021-46700?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Double Free in Saitoha Libsixel

CVE-2021-46700

In libsixel 1.8.6, sixel_encoder_output_without_macro (called from sixel_encoder_encode_frame in encoder.c) has a double free.

Vulnerability class: Double Free

Published 2022-02-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.008 (55.7th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: -0.000

Affected products

Saitoha Libsixel — versions 1.8.6

Weakness classification (CWE)

CWE-415 — Double Free

References

github.com/saitoha/libsixel/issues/158 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-46700?: CVE-2021-46700 is a medium-severity vulnerability in Saitoha Libsixel, classified under Double Free. CVSS score: 6.5/10. Published 2022-02-19.
How severe is CVE-2021-46700?: Medium severity. CVSS v3 base score is 6.5 out of 10.