CVE-2021-45340

MEDIUMNVD 6.56.5—

6.5

In Libsixel prior to and including v1.10.3, a NULL pointer dereference in the stb_image.h component of libsixel allows attackers to cause a denial of service (DOS) via a crafted PICT file.

CVSS v3: 6.5
EG Score: 6.5(medium)
EPSS: 34.6%
KEV: Not listed

Published

January 25, 2022

Last Modified

April 24, 2026

References (2)

cve@mitrehttps://github.com/libsixel/libsixel/issues/51
af854a3a-2127-422b-91ae-364da2661108https://github.com/libsixel/libsixel/issues/51

Weakness Classification(1)

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

CWE-476NULL Pointer Dereference

Data Freshness Timeline

(refreshed 14× 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.

2026-06-05 10:00 UTCOSV refresh
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2026-06-04 13:10 UTCepss_batch
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2026-05-31 22:29 UTCepss_batch
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2026-05-29 13:42 UTCepss_batch
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2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch

Frequently asked(5)

What is CVE-2021-45340?

CVE-2021-45340 is a medium vulnerability published on January 25, 2022. In Libsixel prior to and including v1.10.3, a NULL pointer dereference in the stb_image.h component of libsixel allows attackers to cause a denial of service (DOS) via a crafted PICT file.

When was CVE-2021-45340 disclosed?

CVE-2021-45340 was first published in the National Vulnerability Database on January 25, 2022, 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-2021-45340 actively exploited?

CVE-2021-45340 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 34.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-45340?

CVE-2021-45340 has a CVSS v3 base score of 6.5 (NVD).

How do I remediate CVE-2021-45340?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-45340, 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

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CVE-2021-45340

📅 Published

🔄 Last Modified

🔗 References (2)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-45340?

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Published

Last Modified

References (2)

Frequently asked(5)

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