Vulnerability-Lookup

GHSA-X6PG-X323-JHC4

Vulnerability from github – Published: 2026-10-20 03:32 – Updated: 2026-10-20 03:32

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.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-105297"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-20T01:17:09Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-x6pg-x323-jhc4",
  "modified": "2026-10-20T03:32:43Z",
  "published": "2026-10-20T03:32:43Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-105297"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cloudflare/pingora"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-105297 (GCVE-0-2026-105297)

Vulnerability from cvelistv5 – Published: 2026-10-20 00:40 – Updated: 2026-10-20 00:40

Title

Pingora HTTP/2 server memory exhaustion through unbounded default header-list and concurrent-stream limits

Summary

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.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-770 - Allocation of resources without limits or throttling

Assigner

cloudflare CNA under the mitre root

CNA scorecard – unranked: 8 records in the last 180 days, 10 needed details

References

1 reference

URL	Tags
https://github.com/cloudflare/pingora

Impacted products

1 product

Vendor	Product	Version
Cloudflare	https://github.com/cloudflare/pingora	Affected: 0.1.0 , < 0.8.1 (semver)

Credits

Reported by jro-calif (GitHub)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "https://github.com/cloudflare/pingora",
          "repo": "https://github.com/cloudflare/pingora",
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          "versions": [
            {
              "lessThan": "0.8.1",
              "status": "affected",
              "version": "0.1.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
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          "type": "reporter",
          "value": "Reported by jro-calif (GitHub)"
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      ],
      "descriptions": [
        {
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          "supportingMedia": [
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              "value": "\u003cp\u003eSummary\u003c/p\u003e\u003cp\u003eBefore 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.\u003c/p\u003e\u003cbr\u003e\u003cp\u003eImpact\u003c/p\u003e\u003cp\u003eRemote, 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.\u003c/p\u003e\u003cbr\u003e\u003cp\u003eNote that Cloudflare CDN customers were unaffected, as internal Pingora services at Cloudflare do not have HTTP/2 clients.\u003c/p\u003e\u003cp\u003eMitigation:\u003c/p\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eUpgrade to pingora 0.8.1 or later (fix: \u003ca href=\"https://github.com/cloudflare/pingora/commit/d193c8d49b8b7c1c1ede93183759caa4f6906bbd\"\u003ehttps://github.com/cloudflare/pingora/commit/d193c8d49b8b7c1c1ede93183759caa4f6906bbd\u003c/a\u003e). 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.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eApplications 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.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e"
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        }
      ],
      "metrics": [
        {
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            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
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            "baseScore": 7.5,
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            "confidentialityImpact": "NONE",
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            "scope": "UNCHANGED",
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        "dateUpdated": "2026-10-20T00:40:27.300Z",
        "orgId": "a22f1246-ba21-4bb4-a601-ad51614c1513",
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            }
          ],
          "value": "Mitigation:\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."
        }
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    "datePublished": "2026-10-20T00:40:27.300Z",
    "dateReserved": "2026-10-05T04:18:56.102Z",
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    "state": "PUBLISHED"
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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