CVE-2021-36977

MEDIUMNVD 6.56.5—

6.5

matio (aka MAT File I/O Library) 1.5.20 and 1.5.21 has a heap-based buffer overflow in H5MM_memcpy (called from H5MM_malloc and H5C_load_entry), related to use of HDF5 1.12.0.

CVSS v3: 6.5
EG Score: 6.5(medium)
EPSS: 37.3%
KEV: Not listed

Published

July 20, 2021

Last Modified

November 21, 2024

References (10)

cve@mitrehttps://bugs.chromium.org/p/oss-fuzz/issues/detail?id=31265
cve@mitrehttps://github.com/HDFGroup/hdf5/issues/272
cve@mitrehttps://github.com/google/oss-fuzz-vulns/blob/main/vulns/matio/OSV-2021-440.yaml
cve@mitrehttps://github.com/google/oss-fuzz-vulns/commit/37b781ace1b4228fc36483bb7e30c72ea9d4c3d6
cve@mitrehttps://github.com/google/oss-fuzz/issues/4999
af854a3a-2127-422b-91ae-364da2661108https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=31265
af854a3a-2127-422b-91ae-364da2661108https://github.com/HDFGroup/hdf5/issues/272
af854a3a-2127-422b-91ae-364da2661108https://github.com/google/oss-fuzz-vulns/blob/main/vulns/matio/OSV-2021-440.yaml
af854a3a-2127-422b-91ae-364da2661108https://github.com/google/oss-fuzz-vulns/commit/37b781ace1b4228fc36483bb7e30c72ea9d4c3d6
af854a3a-2127-422b-91ae-364da2661108https://github.com/google/oss-fuzz/issues/4999

Weakness Classification(1)

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

CWE-787Out-of-bounds Write

Data Freshness Timeline

(refreshed 12× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-36977?

CVE-2021-36977 is a medium vulnerability published on July 20, 2021. matio (aka MAT File I/O Library) 1.5.20 and 1.5.21 has a heap-based buffer overflow in H5MMmemcpy (called from H5MMmalloc and H5Cloadentry), related to use of HDF5 1.12.0.

When was CVE-2021-36977 disclosed?

CVE-2021-36977 was first published in the National Vulnerability Database on July 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-2021-36977 actively exploited?

CVE-2021-36977 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 37.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-36977?

CVE-2021-36977 has a CVSS v3 base score of 6.5 (NVD).

How do I remediate CVE-2021-36977?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-36977, 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-2021-36977

📅 Published

🔄 Last Modified

🔗 References (10)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-36977?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (10)

Frequently asked(5)

Related CVEs(same CWE)