What is CVE-2026-2836?

CVE-2026-2836 is a high-severity security vulnerability in pingora-cache (rust), affecting versions <= 0.7.0. It is fixed in 0.8.0.

Which versions of pingora-cache are affected by CVE-2026-2836?

pingora-cache (rust) versions <= 0.7.0 is affected.

Is there a fix for CVE-2026-2836?

Yes. CVE-2026-2836 is fixed in 0.8.0. Upgrade to this version or later.

Is CVE-2026-2836 exploitable, and should I be worried?

Whether CVE-2026-2836 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2026-2836 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-2836?

Upgrade pingora-cache to 0.8.0 or later.

CVE-2026-2836 in pingora-cache

Q: Which versions of pingora-cache are affected by CVE-2026-2836?

pingora-cache (rust) versions <= 0.7.0 is affected.

Q: Is there a fix for CVE-2026-2836?

Yes. CVE-2026-2836 is fixed in 0.8.0. Upgrade to this version or later.

Q: Is CVE-2026-2836 exploitable, and should I be worried?

Whether CVE-2026-2836 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2026-2836 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2026-2836?

Upgrade pingora-cache to 0.8.0 or later.

Summary

Pingora vulnerable to cache poisoning via insecure-by-default cache key

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 and the Cloudflare blog post for more details.

Credits

Disclosed responsibly by Rajat Raghav (@xclow3n) through the Cloudflare Bug Bounty Program.

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.

Affected versions

pingora-cache (<= 0.7.0)

Security releases

pingora-cache → 0.8.0 (rust)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

We strongly suggest users should upgrade to Pingora v.0.8.0 or higher, which removes the default CacheKey implementation.

Frequently Asked Questions

What is CVE-2026-2836? CVE-2026-2836 is a high-severity security vulnerability in pingora-cache (rust), affecting versions <= 0.7.0. It is fixed in 0.8.0.
Which versions of pingora-cache are affected by CVE-2026-2836? pingora-cache (rust) versions <= 0.7.0 is affected.
Is there a fix for CVE-2026-2836? Yes. CVE-2026-2836 is fixed in 0.8.0. Upgrade to this version or later.
Is CVE-2026-2836 exploitable, and should I be worried? Whether CVE-2026-2836 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2026-2836 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2026-2836? Upgrade pingora-cache to 0.8.0 or later.