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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-105297: 0.43% estimated exploitation activity in the next 30 days; percentile 37.23 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Pingora versions prior to 0.8.1 used the h2 crate's default HTTP/2 server limits, a 16 MiB decoded header-list size and no limit on concurrent streams, unless the application set its own. 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. This affects 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. This flaw was corrected in commit d193c8d49b8b7c1c1ede93183759caa4f6906bbd. When no `H2Options` are supplied, Pingora now advertises and enforces a 64 KiB decoded header-list limit and at most 100…

Published by the source

20 Oct 2026, 12:00 UTC

Last modified by the source

26 Oct 2026, 11:15 UTC

Source last checked

26 Oct 2026, 12:45 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from osv record RUSTSEC-2026-0389

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# Patch Next advisory brief: CVE-2026-105297

Advisory: Pingora HTTP/2 server memory exhaustion through unbounded default header-list and concurrent-stream limits
IDs: CVE-2026-105297, GHSA-7gpj-mj4q-x62x
Record: https://patchnext.com/advisories/cve-2026-105297 (revision 1, source checked 26 Oct 2026, 12:45 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: pingora-core 0.8.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io pingora-core: affected >= 0.0.0-0, < 0.8.1; fixed in 0.8.1

## Suggested inspection (read-only)
- crates.io pingora-core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on pingora-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/RUSTSEC-2026-0389 (OSV record RUSTSEC-2026-0389 lists affected ranges: crates.io pingora-core >=0.0.0-0 <0.8.1 (fixed))

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