PT-2026-31006 · Unknown · Fastfeedparser

Redyank · Published 2026-04-07 · Updated 2026-04-08 · CVE-2026-39376

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

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

Name of the Vulnerable Software and Affected Versions FastFeedParser versions prior to 0.5.10

Description FastFeedParser, a high-performance RSS, Atom, and RDF parser, is susceptible to a denial-of-service issue. When the parse() function fetches a URL that redirects via an HTML <meta http-equiv="refresh"> tag, it can enter an infinite recursion loop if the redirect chain is unbounded. This occurs due to a lack of depth limiting, visited URL deduplication, and redirect count capping. An attacker controlling the server can exhaust the Python call stack, leading to a process crash. This issue can also be combined with a Server-Side Request Forgery (SSRF) issue to access internal network targets.

Recommendations Update to FastFeedParser version 0.5.10 or later.

Exploit

Fix

Uncontrolled Recursion

Resource Exhaustion

Weakness Enumeration

CWE-674

CWE-400

Related Identifiers

CVE-2026-39376

GHSA-4GX2-PC4F-WQ37

PYSEC-2026-60

Affected Products

Fastfeedparser

References · 6

• 🔥 https://github.com/kagisearch/fastfeedparser/security/advisories/GHSA-4gx2-pc4f-wq37 · Exploit
• https://osv.dev/vulnerability/GHSA-4gx2-pc4f-wq37 · Vendor Advisory
• https://osv.dev/vulnerability/PYSEC-2026-60 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-39376 · Security Note
• https://github.com/kagisearch/fastfeedparser · Note
• https://twitter.com/CVEnew/status/2041711898811638154 · Twitter Post