CVE-2022-0618: A program using swift-nio-http2 is vulnerable to a denial of service attack, caused by a network peer sending a specially crafted HTTP/2 frame.

A program using swift-nio-http2 is vulnerable to a denial of service attack, caused by a network peer sending a specially crafted HTTP/2 frame.

A program using swift-nio-http2 is vulnerable to a denial of service attack, caused by a network peer sending a specially crafted HTTP/2 frame. This vulnerability is caused by a logical error when parsing a HTTP/2 HEADERS or HTTP/2 PUSH_PROMISE frame where the frame contains padding information without any other data. This logical error caused confusion about the size of the frame, leading to a parsing error. This parsing error immediately crashes the entire process. Sending a HEADERS frame or PUSH_PROMISE frame with HTTP/2 padding information does not require any special permission, so any HTTP/2 connection peer may send such a frame. For clients, this means any server to which they connect may launch this attack. For servers, anyone they allow to connect to them may launch such an attack. The attack is low-effort: it takes very little resources to send an appropriately crafted frame. The impact on availability is high: receiving the frame immediately crashes the server, dropping all in-flight connections and causing the service to need to restart. It is straightforward for an attacker to repeatedly send appropriately crafted frames, so attackers require very few resources to achi

Description from the National Vulnerability Database, published by cve@forums.swift.org

What it means for a small business

If your business uses SwiftNIO HTTP2, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 1.3%, higher than 70% of CVEs. That’s above average: worth scheduling this week. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

Weekly security brief

The flaws that hit local websites, every Friday.

One short email: what got exploited this week, which WordPress plugins broke, and what to check. Unsubscribe in one click.