CVE-2026-2836: Pingora cache Pingora Vulnerable To Cache Poisoning Vulnerability

HIGH
Advisory Identifier: GHSA-f93w-pcj3-rggc
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CWE-639
Published
Advisory Summary

CVE-2026-2836 is a HIGH pingora vulnerable to cache poisoning vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting Pingora cache libraries in the crates.io ecosystem. The issue involves pingora vulnerable to cache poisoning via insecure-by-default cache key. Remediation is available by upgrading affected packages to version 0.8.0.

CVE-2026-2836 at a Glance

CVE Identifier CVE-2026-2836
GHSA Identifier GHSA-f93w-pcj3-rggc
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product Pingora cache
Package Ecosystem crates.io
Published Date
Last Updated

How to Fix CVE-2026-2836

To remediate this vulnerability, upgrade all affected Pingora cache dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pingora-cache fixed: 0.8.0 
Upgrade pingora-cache to 0.8.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for pingora-cache

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-2836, inspect your project dependencies for Pingora cache:

inspect dependencies for pingora-cache

Analyze the terminal output to locate any version of Pingora cache in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.8.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where the system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. In Pingora cache, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact Pingora versions prior to 0.8.0 generated cache keys using only the URI path, excluding critical factors such as the host header. This allows an attacker to poison the cache and serve cross-origin responses to users. This vulnerability affects users of Pingora's alpha proxy caching feature who relied on the default CacheKey implementation. An attacker could exploit this for cross-tenant data leakage in multi-tenant deployments, or serve malicious content to legitimate users by poisoning shared cache entries. Note: Cloudflare customers and Cloudflare's CDN infrastructure were not affected by this vulnerability, as Cloudflare's default cache key implementation uses multiple factors to prevent cache key poisoning and never made use of the previously provided default. ### Patches We strongly suggest users should upgrade to Pingora v.0.8.0 or higher, which removes the default CacheKey implementation. ### Workarounds Do not rely on the provided CacheKey default, and at minimum use the host / :authority and the upstream peer TLS scheme as part of building the CacheKey, as well as other factors that may apply to the deployment e.g. HTTP method. ### References See [CVE-2026-2836](https://cve.org/CVERecord?id=CVE-2026-2836) and the [Cloudflare blog post](https://blog.cloudflare.com/pingora-oss-smuggling-vulnerabilities/) for more details. ### Credits Disclosed responsibly by Rajat Raghav (@xclow3n) through the Cloudflare [Bug Bounty Program](https://www.cloudflare.com/disclosure/).

CVE-2026-2836 Affected Pingora cache Versions

1 component(s)
Fixed Versions:
0.8.0
Product / Package Ecosystem Affected Versions Fixed Version
pingora-cache
 crates.io
< 0.8.0
0.8.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/cloudflare/pingora/security/advisories/GHSA-f93w-pcj3-rggc
NVD — CVE-2026-2836 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-2836
Pingora cache Source Repository REPOSITORY
https://github.com/cloudflare/pingora
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2026-0035.html

Frequently Asked Questions

What is CVE-2026-2836?
CVE-2026-2836 is a security vulnerability in Pingora cache involving Pingora vulnerable to cache poisoning via insecure-by-default cache key under CWE-639: Authorization Bypass Through User-Controlled Key.
Which Pingora cache versions are affected?
Affected versions include releases prior to 0.8.0 across affected packages: pingora-cache.
What version fixes CVE-2026-2836?
Upgrading to 0.8.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pingora-cache affected?
Yes, pingora-cache is affected in releases prior to 0.8.0. Upgrade your dependency to 0.8.0 or later.
What CWE is associated with CVE-2026-2836?
CVE-2026-2836 is classified under CWE-639: Authorization Bypass Through User-Controlled Key (The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.).
How can I check crates.io dependencies for CVE-2026-2836?
Run the dependency tree command: 'inspect dependencies for pingora-cache'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-f93w-pcj3-rggc",
  "modified" : "2026-03-09T20:46:06Z",
  "published" : "2026-03-05T20:57:49Z",
  "aliases" : [ "CVE-2026-2836" ],
  "summary" : "Pingora vulnerable to cache poisoning via insecure-by-default cache key",
  "details" : "### Impact\nPingora versions prior to 0.8.0 generated cache keys using only the URI path, excluding critical factors such as the host header. This allows an attacker to poison the cache and serve cross-origin responses to users.\n\nThis vulnerability affects users of Pingora's alpha proxy caching feature who relied on the default CacheKey implementation. An attacker could exploit this for cross-tenant data leakage in multi-tenant deployments, or serve malicious content to legitimate users by poisoning shared cache entries.\n\nNote: Cloudflare customers and Cloudflare's CDN infrastructure were not affected by this vulnerability, as Cloudflare's default cache key implementation uses multiple factors to prevent cache key poisoning and never made use of the previously provided default.\n\n### Patches\nWe strongly suggest users should upgrade to Pingora v.0.8.0 or higher, which removes the default CacheKey implementation.\n\n### Workarounds\nDo not rely on the provided CacheKey default, and at minimum use the host / :authority and the upstream peer TLS scheme as part of building the CacheKey, as well as other factors that may apply to the deployment e.g. HTTP method. \n\n### References\nSee [CVE-2026-2836](https://cve.org/CVERecord?id=CVE-2026-2836) and the [Cloudflare blog post](https://blog.cloudflare.com/pingora-oss-smuggling-vulnerabilities/) for more details.\n\n### Credits\nDisclosed responsibly by Rajat Raghav (@xclow3n) through the Cloudflare [Bug Bounty Program](https://www.cloudflare.com/disclosure/).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "pingora-cache"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.8.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.7.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/pingora/security/advisories/GHSA-f93w-pcj3-rggc"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-2836"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cloudflare/pingora"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2026-0035.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-05T20:57:49Z",
    "nvd_published_at" : null
  }
}