{"id":"CVE-2026-105299","kind":"vulnerability","aliases":["CVE-2026-105299"],"related":[],"title":"Pingora proxy: client Connection header can strip origin-trusted headers","description":"Summary\n\n\n\nBefore version 0.9.0, the HTTP/1 upstream path in pingora-proxy passed the downstream request through upstream_request_filter and wrote it to the upstream without removing the client's Connection header, other hop-by-hop headers, or the headers Connection nominated, although RFC 9110 Section 7.6.1 requires intermediaries to remove them. The HTTP/2 upstream path already removed Connection and related HTTP/1-specific headers. A client could therefore nominate a header that the application adds in upstream_request_filter (for example, Connection: keep-alive, X-Forwarded-For). A downstream HTTP/1 intermediary that honors Connection would then strip the Pingora-added header before it reached the origin.\n\n\n\n\nImpact\n\n\n\nSpecifically affects chained deployments where an HTTP/1 intermediary between Pingora and the origin processes Connection nominations (for example, Go's net/http/httputil.ReverseProxy) and the origin trusts headers added by that intermediary (for example, X-Forwarded-For for IP-based authorization). A remote, unauthenticated attacker can have those headers removed, potentially bypassing authorization. The reporter demonstrated access to an IP-restricted endpoint using X-Forwarded-For for IP validation on the origin. This is the same class of issue as CVE-2022-31813 in Apache HTTP Server.\n\n\n\n\nNote that Cloudflare CDN customers were unaffected, as no such chained deployment as described above exists with internal Pingora services, and Connection headers are sanitized before arriving at Pingora gateways.\n\n\n\nMitigation:\n\n  *  \n\nUpgrade to pingora 0.9.0 or later. By default, Pingora now removes hop-by-hop and Connection-nominated headers from upstream requests, and rejects requests whose Connection header nominates Host, X-Forwarded-For, X-Forwarded-Host, X-Forwarded-Proto, or a pseudo-header. This is controlled by PeerOptions::http_upstream_request_policy (HttpUpstreamRequestPolicy). Fix commits:  https://github.com/cloudflare/pingora/commit/28c18e6b6b04dd0bd937234e5950049e6d74cded ,  https://github.com/cloudflare/pingora/commit/ca23f1668eca8e78be7ba62ef0edbd458b40eeee \n\n\n  *  \n\nDo not use HttpUpstreamRequestPolicy::preserve() if the origin relies on headers added by Pingora; it restores the old passthrough behavior.\n\n\n  *  \n\nIf you cannot upgrade: in upstream_request_filter, remove the Connection header and every header it nominates before adding trusted headers.","summary":"Before pingora 0.9.0, the HTTP/1 upstream path forwarded the client's Connection header and the headers it names, so a client can make a downstream HTTP/1 intermediary delete headers Pingora added, such as X-Forwarded-For. An unauthenticated remote attacker can thereby bypass IP-based authorization at the origin.","severity":"high","cvss":8.7,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["package","pingora","reverse-proxy","rust","self-hosted"],"not_affected_if":["cloudflare-cdn-only","no-chained-http1-intermediary","origin-ignores-proxy-headers"],"how_to_check":"Check whether the pingora crate in Cargo.lock is below 0.9.0.\nCheck whether an HTTP/1 intermediary (e.g. Go httputil.ReverseProxy) sits between Pingora and the origin.\nCheck whether the origin authorizes requests based on headers added by Pingora.","fix":"Upgrade pingora to 0.9.0 or later, keeping the default HttpUpstreamRequestPolicy (do not use preserve()).\nIf upgrading is not possible, remove Connection and every header it nominates in upstream_request_filter before adding trusted headers.","status":"open","published_at":"2026-10-20T02:17:08+00:00","first_seen_at":"2026-10-23T21:57:19+00:00","triaged_at":"2026-10-23T22:37:24+00:00","updated_at":"2026-10-23T22:37:24+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-23T22:37:24Z","model":"claude-haiku-5-5","output":{"fix":"Upgrade pingora to 0.9.0 or later, keeping the default HttpUpstreamRequestPolicy (do not use preserve()).\nIf upgrading is not possible, remove Connection and every header it nominates in upstream_request_filter before adding trusted headers.","reach":"internet","title":"Pingora proxy: client Connection header can strip origin-trusted headers","impact":"medium","summary":"Before pingora 0.9.0, the HTTP/1 upstream path forwarded the client's Connection header and the headers it names, so a client can make a downstream HTTP/1 intermediary delete headers Pingora added, such as X-Forwarded-For. An unauthenticated remote attacker can thereby bypass IP-based authorization at the origin.","category":"package","who_cares":["pingora","rust","self-hosted","reverse-proxy"],"confidence":0.8,"needs_auth":"no","worst_case":"Remote attacker strips proxy-added headers and bypasses origin IP authorization.","analyst_note":"","how_to_check":"Check whether the pingora crate in Cargo.lock is below 0.9.0.\nCheck whether an HTTP/1 intermediary (e.g. Go httputil.ReverseProxy) sits between Pingora and the origin.\nCheck whether the origin authorizes requests based on headers added by Pingora.","needs_analyst":false,"not_affected_if":["cloudflare-cdn-only","no-chained-http1-intermediary","origin-ignores-proxy-headers"],"user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000652,"input_tokens":3711,"output_tokens":561,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-105299':14A,17A '-2022':272C '-2026':13A,16A '-31813':273C '/cloudflare/pingora/commit/28c18e6b6b04dd0bd937234e5950049e6d74cded':371C '/cloudflare/pingora/commit/ca23f1668eca8e78be7ba62ef0edbd458b40eeee':374C '0.9.0':29B,81C,312C '7.6.1':126C '9110':124C 'access':245C 'add':57B,153C,181C,215C,386C,413C 'affect':190C 'aliv':163C 'alreadi':136C 'although':122C 'apach':275C 'applic':152C 'arriv':304C 'attack':67B,233C 'author':74B,229C,241C 'base':73B,228C 'behavior':394C 'bypass':70B,240C 'cannot':397C 'cdn':281C 'chain':191C,288C 'class':267C 'client':3A,36B,47B,107C,144C 'cloudflar':280C 'commit':368C 'connect':4A,38B,109C,120C,138C,160C,174C,203C,299C,326C,336C,405C 'connection-nomin':325C 'control':359C 'could':145C 'custom':282C 'cve':12A,15A,271C 'default':316C 'delet':54B 'demonstr':244C 'deploy':192C,289C 'describ':291C 'downstream':51B,92C,169C 'endpoint':251C 'everi':408C 'exampl':159C,206C,220C 'exist':293C 'filter':97C,157C,402C 'fix':367C 'forward':34B,62B,166C,223C,255C,342C,346C,350C 'gateway':307C 'github.com':370C,373C 'github.com/cloudflare/pingora/commit/28c18e6b6b04dd0bd937234e5950049e6d74cded':369C 'github.com/cloudflare/pingora/commit/ca23f1668eca8e78be7ba62ef0edbd458b40eeee':372C 'go':207C 'header':5A,11A,39B,42B,55B,110C,116C,119C,142C,149C,182C,214C,237C,300C,328C,337C,356C,385C,406C,409C,415C 'honor':173C 'hop':113C,115C,321C,323C 'hop-by-hop':112C,320C 'host':26B,339C,347C 'http':276C,362C 'http/1':31B,52B,83C,170C,195C 'http/1-specific':141C 'http/2':133C 'httpupstreamrequestpolici':366C,378C 'impact':188C 'intermediari':53B,128C,171C,196C,218C 'intern':295C 'ip':72B,227C,249C,258C 'ip-bas':71B,226C 'ip-restrict':248C 'issu':269C 'keep':162C 'keep-al':161C 'later':314C 'make':49B 'mitig':308C 'name':44B 'net/http/httputil.reverseproxy':209C 'nomin':121C,147C,204C,327C,338C,411C 'note':278C 'old':392C 'origin':9A,77B,187C,201C,212C,262C,382C 'origin-trust':8A 'packag':18B 'pass':90C 'passthrough':393C 'path':33B,85C,135C 'peeropt':361C 'pingora':1A,19B,28B,56B,88C,180C,198C,296C,306C,311C,317C,388C 'pingora-ad':179C 'pingora-proxi':87C 'polici':365C 'potenti':239C 'preserv':379C 'process':202C 'proto':351C 'proxi':2A,22B,89C 'pseudo':355C 'pseudo-head':354C 'reach':185C 'reject':333C 'relat':140C 'reli':383C 'remot':66B,231C 'remov':105C,130C,137C,238C,319C,403C 'report':243C 'request':93C,96C,156C,331C,334C,364C,401C 'requir':127C 'restor':390C 'restrict':250C 'revers':21B 'reverse-proxi':20B 'rfc':123C 'rust':23B 'sanit':302C 'section':125C 'self':25B 'self-host':24B 'server':277C 'servic':297C 'specif':189C 'strip':7A,177C 'summari':78C 'therebi':69B 'therefor':146C 'trust':10A,213C,414C 'unaffect':284C 'unauthent':65B,232C 'upgrad':309C,398C 'upstream':32B,84C,95C,103C,134C,155C,330C,363C,400C 'use':252C,377C 'valid':259C 'version':80C 'whose':335C 'without':104C 'would':175C 'wrote':99C 'x':61B,165C,222C,254C,341C,345C,349C 'x-forwarded-for':60B,164C,221C,253C,340C 'x-forwarded-host':344C 'x-forwarded-proto':348C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T02:17:08+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","cvss_by":"cna@cloudflare.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-105299","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105299","severity":null,"published_at":"2026-10-20T02:17:08+00:00","modified_at":"2026-10-20T20:17:12+00:00","first_seen_at":"2026-10-23T21:57:19+00:00","fetched_at":"2026-10-23T22:28:57+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}