CVE-2020-21049

MEDIUMNVD 6.56.5—

6.5

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.

CVSS v3: 6.5
EG Score: 6.5(medium)
EPSS: 61.9%
KEV: Not listed

Published

September 14, 2021

Last Modified

April 24, 2026

References (10)

cve@mitrehttps://bitbucket.org/netbsd/pkgsrc/commits/970a81d31ec7498e04d09b6b7771cef35f63cd28
cve@mitrehttps://github.com/saitoha/libsixel/blob/master/ChangeLog
cve@mitrehttps://github.com/saitoha/libsixel/commit/0b1e0b3f7b44233f84e5c9f512f8c90d6bbbe33d
cve@mitrehttps://github.com/saitoha/libsixel/issues/74
cve@mitrehttps://github.com/saitoha/libsixel/releases/tag/v1.8.5
af854a3a-2127-422b-91ae-364da2661108https://bitbucket.org/netbsd/pkgsrc/commits/970a81d31ec7498e04d09b6b7771cef35f63cd28
af854a3a-2127-422b-91ae-364da2661108https://github.com/saitoha/libsixel/blob/master/ChangeLog
af854a3a-2127-422b-91ae-364da2661108https://github.com/saitoha/libsixel/commit/0b1e0b3f7b44233f84e5c9f512f8c90d6bbbe33d
af854a3a-2127-422b-91ae-364da2661108https://github.com/saitoha/libsixel/issues/74
af854a3a-2127-422b-91ae-364da2661108https://github.com/saitoha/libsixel/releases/tag/v1.8.5

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-125Out-of-bounds Read

Data Freshness Timeline

(refreshed 17× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-06 13:45 UTCepss_batch
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2026-06-05 10:00 UTCOSV refresh
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Frequently asked(5)

What is CVE-2020-21049?

CVE-2020-21049 is a medium vulnerability published on September 14, 2021. 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.

When was CVE-2020-21049 disclosed?

CVE-2020-21049 was first published in the National Vulnerability Database on September 14, 2021, with the most recent update on April 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2020-21049 actively exploited?

CVE-2020-21049 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 61.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2020-21049?

CVE-2020-21049 has a CVSS v3 base score of 6.5 (NVD).

How do I remediate CVE-2020-21049?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-21049, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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CVE-2020-21049

📅 Published

🔄 Last Modified

🔗 References (10)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2020-21049?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (10)

Frequently asked(5)

Related CVEs(same CWE)