CVE-2026-39376 Details
Description
FastFeedParser is a high performance RSS, Atom and RDF parser. Prior to 0.5.10, when parse() fetches a URL that returns an HTML page containing a <meta http-equiv="refresh"> tag, it recursively calls itself with the redirect URL — with no depth limit, no visited-URL deduplication, and no redirect count cap. An attacker-controlled server that returns an infinite chain of HTML meta-refresh responses causes unbounded recursion, exhausting the Python call stack and crashing the process. This vulnerability can also be chained with the companion SSRF issue to reach internal network targets after bypassing the initial URL check. This vulnerability is fixed in 0.5.10.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 8, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/kagisearch/fastfeedparser/security/advisories/GHSA-4gx2-pc4f-wq37 | CISA-ADP | ExploitVendor Advisory |
| https://github.com/kagisearch/fastfeedparser/security/advisories/GHSA-4gx2-pc4f-wq37 | [email protected] | ExploitVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-674 | Uncontrolled Recursion | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| kagi fastfeedparser | < 0.5.10 |
CPE
Remediation
| |
Change History
6 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 14, 2026 | Initial Analysis | [email protected] |
| Apr 8, 2026 | CVE Modified | CISA-ADP |
| Apr 7, 2026 | New CVE Received | [email protected] |