CVE-2020-11721

MEDIUMNVD 6.56.5—

6.5

load_png in loader.c in libsixel.a in libsixel 1.8.6 has an uninitialized pointer leading to an invalid call to free, which can cause a denial of service.

CVSS v3: 6.5
EG Score: 6.5(medium)
EPSS: 64.8%
KEV: Not listed

Published

April 12, 2020

Last Modified

April 24, 2026

References (2)

cve@mitrehttps://github.com/saitoha/libsixel/issues/134
af854a3a-2127-422b-91ae-364da2661108https://github.com/saitoha/libsixel/issues/134

Weakness Classification(1)

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

CWE-824Access of Uninitialized Pointer

Data Freshness Timeline

(refreshed 10× 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.

2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-31 00:14 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-22 21:16 UTCepss_batch
2026-05-22 21:16 UTCepss_batch
2026-05-22 21:16 UTCepss_batch
2026-05-22 21:16 UTCepss_batch
2026-05-22 21:16 UTCepss_batch

Frequently asked(5)

What is CVE-2020-11721?

CVE-2020-11721 is a medium vulnerability published on April 12, 2020. load_png in loader.c in libsixel.a in libsixel 1.8.6 has an uninitialized pointer leading to an invalid call to free, which can cause a denial of service.

When was CVE-2020-11721 disclosed?

CVE-2020-11721 was first published in the National Vulnerability Database on April 12, 2020, 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-2020-11721 actively exploited?

CVE-2020-11721 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 64.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2020-11721?

CVE-2020-11721 has a CVSS v3 base score of 6.5 (NVD).

How do I remediate CVE-2020-11721?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-11721, 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.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-11721

Explore →

Is Your Infrastructure Affected by CVE-2020-11721?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2020-11721

📅 Published

🔄 Last Modified

🔗 References (2)