What’s Vulnerable › Vulnerabilities

CVE-2020-21049

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-09-14 · updated 2026-06-17
• Weakness: CWE-125

Description

An invalid read in the stb_image.h component of libsixel prior to v1.8.5 allows attackers to cause a denial of service (DOS) via a crafted PSD file.

Affected products

• saitoha libsixel: before 1.8.5 — fixed in 1.8.5

How to fix

Upgrade to a fixed version: saitoha libsixel 1.8.5. Check the vendor advisory for mitigations.

References

• https://bitbucket.org/netbsd/pkgsrc/commits/970a81d31ec7498e04d09b6b7771cef35f63cd28
• https://github.com/saitoha/libsixel/blob/master/ChangeLog
• https://github.com/saitoha/libsixel/commit/0b1e0b3f7b44233f84e5c9f512f8c90d6bbbe33d
• https://github.com/saitoha/libsixel/issues/74
• https://github.com/saitoha/libsixel/releases/tag/v1.8.5
• https://bitbucket.org/netbsd/pkgsrc/commits/970a81d31ec7498e04d09b6b7771cef35f63cd28
• https://github.com/saitoha/libsixel/blob/master/ChangeLog
• https://github.com/saitoha/libsixel/commit/0b1e0b3f7b44233f84e5c9f512f8c90d6bbbe33d
• https://github.com/saitoha/libsixel/issues/74
• https://github.com/saitoha/libsixel/releases/tag/v1.8.5

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