# CVE-2026-105297: Pingora HTTP/2 server memory exhaustion via header injection

Source: https://junglewise.ai/threats/cve-2026-105297-summary-before-version-0-8-1-pingora-s-http-2-server-used-the-h2  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-105297 · Severity: high · CVSS 7.5 · Published 2026-10-20

Pingora is a reverse proxy and load balancer that handles HTTP/2 connections. An attacker can send specially crafted HTTP/2 headers that cause the server to allocate excessive memory across many concurrent streams, exhausting available memory and crashing the service, disrupting traffic to downstream applications.

Technologies: [Cloudflare Pingora](https://junglewise.ai/threats/technologies/pingora), [pingora-core (crates.io)](https://junglewise.ai/threats/technologies/pingora-core). Vendors: [Cloudflare](https://junglewise.ai/threats/vendors/cloudflare), [crates.io](https://junglewise.ai/threats/vendors/crates-io).

## Quick answers

**Is CVE-2026-105297 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105297 being exploited in the wild.

**How severe is CVE-2026-105297?** High severity, with a CVSS score of 7.5, published 20 October 2026.

**Which products and versions are affected?** Cloudflare Pingora before 0.8.1; pingora-core (crates.io) SEMVER:introduced=0.0.0-0,fixed=0.8.1.

**Is there a fix for CVE-2026-105297?** Yes. pingora-core (crates.io): upgrade to 0.8.1 or later. Until then: Upgrade to Pingora 0.8.1 or later, which enforces a 64 KiB decoded header-list limit and maximum of 100 concurrent streams by default. Applications supplying custom H2Options must explicitly set max_header_list_size and max_concurrent_streams, or use the default_h2_options() function on 0.8.1+. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-105297 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-105297?** Check whether you run Cloudflare Pingora or pingora-core (crates.io) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- pingora-core (crates.io): upgrade to 0.8.1 or later

  ```sh
  cargo update -p pingora-core
  ```


Upgrade to Pingora 0.8.1 or later, which enforces a 64 KiB decoded header-list limit and maximum of 100 concurrent streams by default. Applications supplying custom H2Options must explicitly set max_header_list_size and max_concurrent_streams, or use the default_h2_options() function on 0.8.1+.

## Technical details

Pingora's HTTP/2 server implementation did not enforce limits on decoded header-list size and concurrent streams by default, instead relying on the h2 crate's permissive defaults. An unauthenticated remote attacker can craft HPACK-encoded headers with 1-byte references to force header field allocation across unlimited concurrent streams on a single connection, then use HTTP/2 flow control to keep streams open and prevent resource cleanup. This leads to memory exhaustion and denial of service.

## Affected products

- Cloudflare Pingora before 0.8.1

## Identifiers

- CVE-2026-105297
- GHSA-7gpj-mj4q-x62x
- RUSTSEC-2026-0389

## Timeline

- 2026-10-20: disclosed

## Related threats

- [Cloudflare Pingora HTTP/1 Connection header bypass](https://junglewise.ai/threats/cve-2026-105299-summary-before-version-0-9-0-the-http-1-upstream-path-in-pingora)
- [Pingora HTTP/2 host mismatch and cache poisoning](https://junglewise.ai/threats/cve-2026-105298-summary-before-version-0-9-0-pingora-accepted-http-2-requests)
- [Duplicate Advisory: HTTP Request Smuggling via Premature Upgrade](https://junglewise.ai/threats/duplicate-advisory-http-request-smuggling-via-premature-upgrade-80d9b682)
- [Duplicate Advisory: HTTP Request Smuggling via HTTP/1.0 and Transfer-Encoding Misparsing](https://junglewise.ai/threats/duplicate-advisory-http-request-smuggling-via-http-1-0-and-transfer-e49a45ff)
- [RUSTSEC-2026-0034 - HTTP Request Smuggling via HTTP/1.0 and Transfer-Encoding Misparsing](https://junglewise.ai/threats/cve-2026-2835-pingora-has-http-request-smuggling-via-http-1-0-and-transfer)