CVE-2026-110223: Kavita 0.9.0 through 0.9.1.4 SSRF Blocklist Bypass via upload-cbl-file Endpoint

Severity: low (CVSS 3.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-13 · updated 2026-10-14
Weakness: CWE-918

Description

Kavita 0.9.0 through 0.9.1.4 contains a server-side request forgery vulnerability that allows authenticated users to bypass the SSRF blocklist through DNS rebinding or HTTPS redirects. Attackers can submit a URL to POST /api/Cbl/upload-cbl-file whose host rebinds or redirects to internal addresses after validation, enabling blind internal port and service probing.

Affected products

Kareadita Kavita: from 0.9.0 through 0.9.1.4

References

https://github.com/Kareadita/Kavita
https://github.com/Kareadita/Kavita/blob/879b8b73eb41d66f88dde8eb874cc99a3397eb11/Kavita.Common/Helpers/FlurlConfiguration.cs#L46-L89
https://github.com/Kareadita/Kavita/blob/879b8b73eb41d66f88dde8eb874cc99a3397eb11/Kavita.Server/Controllers/CBLController.cs#L82-L108
https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/kavita-cbl-url-preflight-ssrf
https://www.vulncheck.com/advisories/kavita-0.9.0-through-0.9.1.4-ssrf-blocklist-bypass-via-upload-cbl-file-endpoint

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