CVE-2020-9856

MEDIUMNVD 5.35.3—Weaponized

5.3

This issue was addressed with improved checks. This issue is fixed in macOS Catalina 10.15.5. An application may be able to gain elevated privileges.

CVSS v3: 5.3
EG Score: 5.3(medium)
EPSS: 95.4%
KEV: Not listed

Published

June 9, 2020

Last Modified

November 21, 2024

References (2)

product-security@applehttps://support.apple.com/HT211170
af854a3a-2127-422b-91ae-364da2661108https://support.apple.com/HT211170

Weakness Classification(1)

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

CWE-119Buffer Operations Within Bounds (Buffer Overflow)

Data Freshness Timeline

(refreshed 9× 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.

2026-06-07 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 22:45 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
2026-05-31 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
2026-05-29 13:42 UTCEPSS rescore
2026-05-28 13:43 UTCEPSS rescore
2026-05-28 13:43 UTCEPSS rescore
2026-05-27 13:39 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Metasploit module). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

Metasploitexploit/osx/browser/safari_in_operator_side_effect✓ verified
First seen Mar 18, 2020
Safari in Operator Side Effect Exploit
Open source ↗

Frequently asked(5)

What is CVE-2020-9856?

CVE-2020-9856 is a medium vulnerability published on June 9, 2020. This issue was addressed with improved checks. This issue is fixed in macOS Catalina 10.15.5. An application may be able to gain elevated privileges.

When was CVE-2020-9856 disclosed?

CVE-2020-9856 was first published in the National Vulnerability Database on June 9, 2020, 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-2020-9856 actively exploited?

CVE-2020-9856 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 95.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2020-9856?

CVE-2020-9856 has a CVSS v3 base score of 5.3 (NVD).

How do I remediate CVE-2020-9856?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-9856, 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-2020-9856

📅 Published

🔄 Last Modified

🔗 References (2)

Weakness Classification(1)

Data Freshness Timeline

Publicly available exploits

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2020-9856?

🔗 Related CVEs(same CWE)

Same CWE

Published

Last Modified

References (2)

Frequently asked(5)

Related CVEs(same CWE)