Is CVE-2026-35031 in the CISA KEV catalog?

No. CVE-2026-35031 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-35031?

CVE-2026-35031 has a CVSS v3 base score of 9.9 (CRITICAL).

What is the EPSS score for CVE-2026-35031?

CVE-2026-35031 has an EPSS score of 0.75% (50th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-35031

CRITICAL

9.9

CVSS v3

NVD

Description

Jellyfin is an open source self hosted media server. Versions prior to 10.11.7 contain a vulnerability chain in the subtitle upload endpoint (POST /Videos/{itemId}/Subtitles), where the Format field is not validated, allowing path traversal via the file extension and enabling arbitrary file write. This arbitrary file write can be chained into arbitrary file read via .strm files, database extraction, admin privilege escalation, and ultimately remote code execution as root via ld.so.preload. Exploitation requires an administrator account or a user that has been explicitly granted the "Upload Subtitles" permission. This issue has been fixed in version 10.11.7. If users are unable to upgrade immediately, they can grant non-administrator users Subtitle upload permissions to reduce attack surface.

CWE-20Improper Input Validation CWE-22Path Traversal CWE-187

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeChanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploit Intelligence

0.75%probability of exploitation in 30 days

50thpercentile

Moderate risk: more likely to be exploited than 50% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.