CVE-2026-105297

Source
https://cve.org/CVERecord?id=CVE-2026-105297
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-105297.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-105297
Published
2026-10-20T00:40:27Z
Modified
2026-10-20T11:15:59Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
Pingora HTTP/2 server memory exhaustion through unbounded default header-list and concurrent-stream limits
Details

Summary

Before version 0.8.1, Pingora's HTTP/2 server used the h2 crate's 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.

Impact

Remote, 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.

Note that Cloudflare CDN customers were unaffected, as internal Pingora services at Cloudflare do not have HTTP/2 clients.

Mitigation:

Upgrade 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.

Applications 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.

Database specific
{
    "cna_assigner":  "cloudflare",
    "cwe_ids":  [
        "CWE-770"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/105xxx/CVE-2026-105297.json"
}
References

Affected packages

Git / github.com/cloudflare/pingora

Affected ranges

Type
GIT
Repo
https://github.com/cloudflare/pingora
Events
Database specific
Show details
{
    "extracted_events":  [
        {
            "introduced":  "0.1.0"
        },
        {
            "fixed":  "0.8.1"
        }
    ],
    "source":  "AFFECTED_FIELD"
}

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-105297.json"