CVE-2026-49246

CVE-2026-49246 is a low-severity vulnerability with a CVSS 4.0 base score of 1.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.

Key facts

Description

Jellyfin is an open source self hosted media server. Prior to 10.11.10, a specifically crafted MKV file containing forged filename tags can be leveraged to exploit missing path sanitization during playback. Jellyfin treats the MKV file name tag on MKV attachments as trusted and passes it unsanitized into Path.Combine(attachmentFolder, fileName) inside PathManager.GetAttachmentPath. Because .NET's Path.Combine neither normalises .. nor rejects a rooted second argument, a crafted MKV can redirect Jellyfin's MKV attachment extraction to any absolute path on disk. This triggers on any playback action of the affected video on a client which will attempt to burn in the subtitles by default.g This vulnerability is fixed in 10.11.10.

Frequently asked questions

What is CVE-2026-49246?
Jellyfin is an open source self hosted media server. Prior to 10.11.10, a specifically crafted MKV file containing forged filename tags can be leveraged to exploit missing path sanitization during playback. Jellyfin treats the MKV file name tag on MKV attachments as trusted and passes it unsanitized into Path.Combine(attachmentFolder, fileName) inside PathManager.GetAttachmentPath. Because .NET's Path.Combine neither normalises .. nor rejects a rooted second argument, a crafted MKV can redirect Jellyfin's MKV attachment extraction to any absolute path on disk. This triggers on any playback action of the affected video on a client which will attempt to burn in the subtitles by default.g This vulnerability is fixed in 10.11.10.
How severe is CVE-2026-49246?
CVE-2026-49246 has a CVSS 4.0 base score of 1.7, rated low severity.
Is CVE-2026-49246 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-49246?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-49246 have an EU (EUVD) identifier?
Yes. CVE-2026-49246 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39029.
When was CVE-2026-49246 published?
CVE-2026-49246 was published on 2026-06-24 and last updated on 2026-06-25.

References

Other CWE-22 (Path Traversal) vulnerabilities

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