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High · 7.5 Public exploit CVE-2026-39376 EUVD-2026-19915GHSA-4gx2-pc4f-wq37PYSEC-2026-60

FastFeedParser has an infinite redirect loop DoS via meta-refresh chain

Published Apr 7, 2026 · Updated Apr 8, 2026 · Assigned by GitHub_M

Vendor: kagisearch Product: fastfeedparser Package: fastfeedparser Ecosystem: PyPI

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.

Affected products

VendorProductAffectedFixed
kagisearch fastfeedparser < 0.5.10 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

  • redyank/CVE-2026-39376 ★ 0 · Apr 10, 2026

    CVE-2026-39376(Infinite redirect loop DoS via meta-refresh chain)

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI fastfeedparser < 0.5.10 0.5.10 GHSA-4gx2-pc4f-wq37

References