--- title: Hardening PHP against filter chain attacks | daily.dev description: A PHP internals mailing list thread discussing a proposed RFC to harden PHP against filter chain attacks by limiting the maximum number of filters allowed in... canonical: https://daily.dev/posts/hardening-php-against-filter-chain-attacks-xdabv0878 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Hardening PHP against filter chain attacks | daily.dev og:description: A PHP internals mailing list thread discussing a proposed RFC to harden PHP against filter chain attacks by limiting the maximum number of filters allowed in... og:url: https://daily.dev/posts/hardening-php-against-filter-chain-attacks-xdabv0878 og:image: https://api.daily.dev/og/posts/xdABv0878.png og:image:alt: Hardening PHP against filter chain attacks og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Hardening PHP against filter chain attacks **[externals.io](https://daily.dev/sources/externals)** · 10 min read · 0 upvotes · 0 comments ## Summary A PHP internals mailing list thread discussing a proposed RFC to harden PHP against filter chain attacks by limiting the maximum number of filters allowed in php://filter URLs. The proposal suggests a default limit of 16 filters (most exploits require 50-100+), with the limit configurable via a stream context option (filter.max_filter_count). The thread covers open questions including the exact limit value, whether to use a hard error or deprecation warning first, and how to handle the dechunk filter bug. A vote on the RFC opened June 5, 2026, closing June 26, 2026, with participants generally in favor. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Hardening PHP against filter chain attacks](https://daily.dev/posts/hardening-php-against-filter-chain-attacks-gdt4ai17e) · externals.io · 0 upvotes · 0 comments - [Hardening PHP against filter chain attacks](https://daily.dev/posts/hardening-php-against-filter-chain-attacks-ng2kpdsl8) · externals.io · 0 upvotes · 0 comments - [Hardening PHP against filter chain attacks](https://daily.dev/posts/hardening-php-against-filter-chain-attacks-wv3dmmn7o) · externals.io · 0 upvotes · 0 comments - [Hardening PHP against filter chain attacks](https://daily.dev/posts/hardening-php-against-filter-chain-attacks-okpdglrem) · externals.io · 0 upvotes · 0 comments - [Hardening PHP against filter chain attacks](https://daily.dev/posts/hardening-php-against-filter-chain-attacks-nlpq8fdps) · externals.io · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#php](https://daily.dev/tags/php) [View this post on daily.dev](https://daily.dev/posts/hardening-php-against-filter-chain-attacks-xdabv0878) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Hardening PHP against filter chain attacks","url":"https://daily.dev/posts/hardening-php-against-filter-chain-attacks-xdabv0878","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/hardening-php-against-filter-chain-attacks-xdabv0878"},"datePublished":"2026-06-11T13:13:36.454Z","dateModified":"2026-06-11T13:14:03.382Z","description":"A PHP internals mailing list thread discussing a proposed RFC to harden PHP against filter chain attacks by limiting the maximum number of filters allowed in...","image":"https://media.daily.dev/image/upload/s--P4t4XyoV--/f_auto/v1722860399/public/Placeholder%2001","thumbnailUrl":"https://media.daily.dev/image/upload/s--P4t4XyoV--/f_auto/v1722860399/public/Placeholder%2001","isAccessibleForFree":true,"articleSection":"externals.io","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"externals.io","logo":"https://media.daily.dev/image/upload/s--9i0zxASK--/f_auto,q_auto/v1780213616/logos/externals?_a=BAMAMiWQ0","url":"https://daily.dev/sources/externals"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/hardening-php-against-filter-chain-attacks-xdabv0878","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"security,php","timeRequired":"PT10M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"externals.io","item":"https://daily.dev/sources/externals"},{"@type":"ListItem","position":3,"name":"Hardening PHP against filter chain attacks"}]} ```