CVE-2021-28906

HIGHNVD 7.57.5—

7.5

In function read_yin_leaf() in libyang <= v1.0.225, it doesn't check whether the value of retval->ext[r] is NULL. In some cases, it can be NULL, which leads to the operation of retval->ext[r]->flags that results in a crash.

CVSS v3: 7.5
EG Score: 7.5(medium)
EPSS: 58.8%
KEV: Not listed

Published

May 20, 2021

Last Modified

November 21, 2024

References (4)

cve@mitrehttps://github.com/CESNET/libyang/issues/1455
cve@mitrehttps://security.gentoo.org/glsa/202107-54
af854a3a-2127-422b-91ae-364da2661108https://github.com/CESNET/libyang/issues/1455
af854a3a-2127-422b-91ae-364da2661108https://security.gentoo.org/glsa/202107-54

Weakness Classification(1)

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

CWE-252Unchecked Return Value

Data Freshness Timeline

(refreshed 7× in last 7d / 7× 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.

2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 16:18 UTCEG score recompute
2026-05-26 16:18 UTCGHSA enrichment
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2021-28906?

CVE-2021-28906 is a high vulnerability published on May 20, 2021. In function readyinleaf() in libyang <= v1.0.225, it doesn't check whether the value of retval->ext[r] is NULL. In some cases, it can be NULL, which leads to the operation of retval->ext[r]->flags that results in a crash.

When was CVE-2021-28906 disclosed?

CVE-2021-28906 was first published in the National Vulnerability Database on May 20, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-28906 actively exploited?

CVE-2021-28906 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 58.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-28906?

CVE-2021-28906 has a CVSS v3 base score of 7.5 (NVD).

How do I remediate CVE-2021-28906?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-28906, 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-2021-28906

📅 Published

🔄 Last Modified

🔗 References (4)