CVE-2021-25827

CRITICALNVD 9.89.8—

9.8

Emby Server < 4.7.12.0 is vulnerable to a login bypass attack by setting the X-Forwarded-For header to a local IP-address.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 57.8%
KEV: Not listed

Published

June 28, 2023

Last Modified

November 21, 2024

References (6)

cve@mitrehttps://emby.media/community/index.php?/topic/98191-emby-server-46-released/
cve@mitrehttps://github.com/EmbySupport/security/security/advisories/GHSA-fffj-6fr6-3fgf
cve@mitrehttps://github.com/MediaBrowser/Emby/issues/3784
af854a3a-2127-422b-91ae-364da2661108https://emby.media/community/index.php?/topic/98191-emby-server-46-released/
af854a3a-2127-422b-91ae-364da2661108https://github.com/EmbySupport/security/security/advisories/GHSA-fffj-6fr6-3fgf
af854a3a-2127-422b-91ae-364da2661108https://github.com/MediaBrowser/Emby/issues/3784

Weakness Classification(1)

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

CWE-290Authentication Bypass by Spoofing

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 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-24 22:16 UTCEG score recompute
2026-05-24 22:16 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2021-25827?

CVE-2021-25827 is a critical vulnerability published on June 28, 2023. Emby Server < 4.7.12.0 is vulnerable to a login bypass attack by setting the X-Forwarded-For header to a local IP-address.

When was CVE-2021-25827 disclosed?

CVE-2021-25827 was first published in the National Vulnerability Database on June 28, 2023, 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-2021-25827 actively exploited?

CVE-2021-25827 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 57.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-25827?

CVE-2021-25827 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2021-25827?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-25827, 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-2021-25827

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CVE-2021-25827

📅 Published

🔄 Last Modified

🔗 References (6)