CVE-2021-21402
CVE-2021-21402 is a high-severity vulnerability in Jellyfin with a CVSS 3.x base score of 7.7. Its EPSS exploit-prediction score of 80% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-22.
Key facts
- Severity: High (CVSS 3.x base score 7.7)
- CVSS v2: 4.0
- EPSS exploit prediction: 80% (100th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-22
- Affected product: Jellyfin
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2021-21402?
- 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.
- How severe is CVE-2021-21402?
- CVE-2021-21402 has a CVSS 3.x base score of 7.7, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2021-21402 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 80% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-21402?
- CVE-2021-21402 affects Jellyfin. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-21402?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-21402 published?
- CVE-2021-21402 was published on 2021-03-23 and last updated on 2026-06-17.
References
- https://github.com/jellyfin/jellyfin/commit/0183ef8e89195f420c48d2600bc0b72f6d3a7fd7
- https://github.com/jellyfin/jellyfin/releases/tag/v10.7.1
- https://github.com/jellyfin/jellyfin/security/advisories/GHSA-wg4c-c9g9-rxhx
Affected products (1)
- cpe:2.3:a:jellyfin:jellyfin:*:*:*:*:*:*:*:*
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