CVE-2021-21402
MediumExploitedIn Jellyfin before version 10.7.1, with certain endpoints, well crafted requests will allow arbitrary file read from a Jellyfin server's file system.
Published Mar 23, 2021 · Updated Aug 7, 2026 · Also known as GHSA-wg4c-c9g9-rxhx
Key Facts
Patch immediately- CVE-2021-21402 is a medium-severity vulnerability (CVSS 6.5 v3.1) affecting Jellyfin.
- It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Oct 17, 2023. No public exploit code is known.
- EPSS estimates a 79% probability of exploitation in the next 30 days.
- Fixed versions are available, including Jellyfin 10.7.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS (30-day exploit likelihood)
79%
Higher than 99.5% of all scored CVEs
Exploited in the wild
Yes
2 catalog listings
Public exploit code
None known
Get the full CVE-2021-21402 brief as a PDF
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Description
Jellyfin is a Free Software Media System. In Jellyfin before version 10.7.1, with certain endpoints, well crafted requests will allow arbitrary file read from a Jellyfin server's file system. This issue is more prevalent when Windows is used as the host OS. Servers that are exposed to the public Internet are potentially at risk. This is fixed in version 10.7.1. As a workaround, users may be able to restrict some access by enforcing strict security permissions on their filesystem, however, it is recommended to update as soon as possible.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Nov 13, 2023 | n/a | Not reported |
| CIRCL KEV | Oct 17, 2023 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| JellyfinJellyfin | >= < 10.7.1 | 10.7.1 |
Patched Releases
Jellyfin
10.7.1
Timeline
Publicly disclosed
Mar 23, 2021
Added to CIRCL KEV
Oct 17, 2023
Added to Industry KEV feed
Nov 13, 2023
Last updated
Aug 7, 2026
Weakness Type
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
References
- advisoryhttps://github.com/jellyfin/jellyfin/releases/tag/v10.7.1
- advisoryhttps://github.com/jellyfin/jellyfin/security/advisories/GHSA-wg4c-c9g9-rxhx
- patchhttps://github.com/jellyfin/jellyfin/commit/0183ef8e89195f420c48d2600bc0b72f6d3a7fd7
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
Jellyfin is a Free Software Media System.
Affected: Jellyfin versions >= < 10.7.1. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Oct 17, 2023.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Jellyfin 10.7.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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