{"id":"EUVD-2026-104678","enisaUuid":"2ba2fd0a-6b3a-373e-9198-cbeba74e9c5f","description":"Summary\n\n\n\nBefore version 0.8.1, Pingora\u0027s HTTP/2 server used the h2 crate\u0027s default limits unless the application set its own 16 MiB decoded header-list size and no limit on concurrent streams. A remote, unauthenticated client can send 1-byte HPACK references to a near-empty header, making the server allocate hundreds of thousands of header fields per stream across an unlimited number of streams on one connection, and use HTTP/2 flow control to keep those streams open. This can exhaust memory and degrade or terminate the Pingora process.\n\n\n\n\nImpact\n\n\n\nRemote, unauthenticated denial of service against any Pingora service that terminates HTTP/2 (h2 or h2c) without explicitly setting max_header_list_size and max_concurrent_streams. The reporter showed that a single connection could get a Pingora process with a 2 GiB memory limit OOM-killed.\n\n\n\n\nNote that Cloudflare CDN customers were unaffected, as internal Pingora services at Cloudflare do not have HTTP/2 clients.\n\n\n\nMitigation:\n\n  *  \n\nUpgrade to pingora 0.8.1 or later (fix:  https://github.com/cloudflare/pingora/commit/d193c8d49b8b7c1c1ede93183759caa4f6906bbd ). When no H2Options are supplied, Pingora now advertises and enforces a 64 KiB decoded header-list limit and at most 100 concurrent streams per connection.\n\n\n  *  \n\nApplications that supply their own H2Options are not covered by these defaults and must set max_header_list_size and max_concurrent_streams explicitly (this also works on versions before 0.8.1), or, on 0.8.1 and later, start from pingora_core::protocols::http::v2::server::default_h2_options(). H2Options::default() does not include these limits.","datePublished":"Oct 20, 2026, 12:40:27 AM","dateUpdated":"Oct 20, 2026, 7:20:35 PM","baseScore":7.5,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","references":"https://github.com/cloudflare/pingora\n","aliases":"CVE-2026-105297\nGHSA-x6pg-x323-jhc4\n","assigner":"cloudflare","epss":0.43,"enisaIdProduct":[{"id":"bbb0bb3c-ba2f-3d9e-84ec-bef63b0f076c","product":{"name":"https://github.com/cloudflare/pingora","vendor":{"name":"Cloudflare"}},"product_version":"0.1.0 \u003c0.8.1"}],"enisaIdVendor":[{"id":"50cec7ab-b9ae-3b34-97d6-ef37fd21be5e","vendor":{"name":"Cloudflare"}}],"enisaIdVulnerability":[{"id":"ab592904-3845-3cea-a968-a73590034b0f","vulnerability":{"id":"CVE-2026-105297","description":"Summary\n\n\n\nBefore version 0.8.1, Pingora\u0027s HTTP/2 server used the h2 crate\u0027s default limits unless the application set its own 16 MiB decoded header-list size and no limit on concurrent streams. A remote, unauthenticated client can send 1-byte HPACK references to a near-empty header, making the server allocate hundreds of thousands of header fields per stream across an unlimited number of streams on one connection, and use HTTP/2 flow control to keep those streams open. This can exhaust memory and degrade or terminate the Pingora process.\n\n\n\n\nImpact\n\n\n\nRemote, unauthenticated denial of service against any Pingora service that terminates HTTP/2 (h2 or h2c) without explicitly setting max_header_list_size and max_concurrent_streams. The reporter showed that a single connection could get a Pingora process with a 2 GiB memory limit OOM-killed.\n\n\n\n\nNote that Cloudflare CDN customers were unaffected, as internal Pingora services at Cloudflare do not have HTTP/2 clients.\n\n\n\nMitigation:\n\n  *  \n\nUpgrade to pingora 0.8.1 or later (fix:  https://github.com/cloudflare/pingora/commit/d193c8d49b8b7c1c1ede93183759caa4f6906bbd ). When no H2Options are supplied, Pingora now advertises and enforces a 64 KiB decoded header-list limit and at most 100 concurrent streams per connection.\n\n\n  *  \n\nApplications that supply their own H2Options are not covered by these defaults and must set max_header_list_size and max_concurrent_streams explicitly (this also works on versions before 0.8.1), or, on 0.8.1 and later, start from pingora_core::protocols::http::v2::server::default_h2_options(). H2Options::default() does not include these limits.","datePublished":"Oct 20, 2026, 12:40:27 AM","dateUpdated":"Oct 20, 2026, 7:20:35 PM","status":"PUBLISHED","baseScore":7.5,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","references":"https://github.com/cloudflare/pingora\n","enisa_id":"EUVD-2026-104678\n","assigner":"cloudflare","epss":0.43,"dataProcessed":"Nov 2, 2026, 7:16:47 AM","vulnerabilityProduct":[{"id":"32394e71-0674-357b-88ad-0d6c74de7e45","product":{"name":"https://github.com/cloudflare/pingora","vendor":{"name":"Cloudflare"}},"product_version":"0.1.0 \u003c0.8.1"}],"vulnerabilityVendor":[{"id":"97ae6825-656e-33f9-a28c-270b77703647","vendor":{"name":"Cloudflare"}}]}},{"id":"e4deebec-dbce-3768-9df7-16c83a6c5848","vulnerability":{"id":"GHSA-x6pg-x323-jhc4","description":"Summary\n\n\n\nBefore version 0.8.1, Pingora\u0027s HTTP/2 server used the h2 crate\u0027s default limits unless the application set its own 16 MiB decoded header-list size and no limit on concurrent streams. A remote, unauthenticated client can send 1-byte HPACK references to a near-empty header, making the server allocate hundreds of thousands of header fields per stream across an unlimited number of streams on one connection, and use HTTP/2 flow control to keep those streams open. This can exhaust memory and degrade or terminate the Pingora process.\n\n\n\n\nImpact\n\n\n\nRemote, unauthenticated denial of service against any Pingora service that terminates HTTP/2 (h2 or h2c) without explicitly setting max_header_list_size and max_concurrent_streams. The reporter showed that a single connection could get a Pingora process with a 2 GiB memory limit OOM-killed.\n\n\n\n\nNote that Cloudflare CDN customers were unaffected, as internal Pingora services at Cloudflare do not have HTTP/2 clients.\n\n\n\nMitigation:\n\n  *  \n\nUpgrade to pingora 0.8.1 or later (fix:  https://github.com/cloudflare/pingora/commit/d193c8d49b8b7c1c1ede93183759caa4f6906bbd ). When no H2Options are supplied, Pingora now advertises and enforces a 64 KiB decoded header-list limit and at most 100 concurrent streams per connection.\n\n\n  *  \n\nApplications that supply their own H2Options are not covered by these defaults and must set max_header_list_size and max_concurrent_streams explicitly (this also works on versions before 0.8.1), or, on 0.8.1 and later, start from pingora_core::protocols::http::v2::server::default_h2_options(). H2Options::default() does not include these limits.","datePublished":"Oct 20, 2026, 3:32:43 AM","dateUpdated":"Oct 20, 2026, 3:32:43 AM","baseScore":0.0,"references":"https://nvd.nist.gov/vuln/detail/CVE-2026-105297\nhttps://github.com/cloudflare/pingora\n","enisa_id":"EUVD-2026-104678\n","aliases":"CVE-2026-105297\nGHSA-x6pg-x323-jhc4\n","epss":0.0,"dataProcessed":"Nov 1, 2026, 2:08:27 AM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}}],"enisaIdAdvisory":[]}