CVE-2020-21677

6.5 mediumEPSS 0.9%

Medium (6.5) in saitoha libsixel. EPSS 0.9% chance of exploitation in the next 30 days.

A heap-based buffer overflow in the sixel_encoder_output_without_macro function in encoder.c of Libsixel 1.8.4 allows attackers to cause a denial of service (DOS) via converting a crafted PNG file into Sixel format.

Severity

CVSS 3.1

6.5 medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS: 0.9% chance of exploitation in the next 30 days; higher than 59% of CVEs (scores of 2026-10-31)
CWE: CWE-787
Published: 2021-08-10
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

saitoha:libsixel

References

https://github.com/saitoha/libsixel/issues/123
https://github.com/saitoha/libsixel/issues/123

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