Vulnerabilities

Vulnerability · CVE-2021-21402

jellyfin jellyfin Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Published Nov 13, 2023 · catalog updated Nov 13, 2023 · jellyfin jellyfin Improper Limitation

Patch now

CVE-2021-21402 is in the CISA known-exploited catalog. Confirm jellyfin jellyfin Improper Limitation against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (jellyfin jellyfin Improper Limitation).
  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Unknown—
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
79.31%
Remediation
Remediation guidance
Affected products
vendor jellyfin jellyfin

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. Initial-access exploit intelligence.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor jellyfin jellyfinversion unspecified

How to fix CVE-2021-21402

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2021-21402 is in the CISA known-exploited catalog. Confirm jellyfin jellyfin Improper Limitation against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What should an analyst verify?

No weakness class is stored. EPSS 79.31%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Nov 13, 2023 · VulnCheck KEV

    Detected

    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 t

  2. Nov 13, 2023 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Sources

  • CVE.orgVulnerability recordCVE-2021-21402

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-21402

    30-day exploitation probability 79.3%

    first.org
  • VulnCheck KEVConfirmed exploitationCVE-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 expos

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.