CVE-2026-2836
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA cache poisoning vulnerability has been found in the Pingora HTTP proxy framework’s default cache key construction. The issue occurs because the default HTTP cache key implementation generates cache keys using only the URI path, excluding critical factors such as the host header (authority). Operators relying on the default are vulnerable to cache poisoning, and cross-origin responses may be improperly served to users. Impact 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, poison the cache so that users from one tenant receive cached responses from another tenant * Cache poisoning attacks: Serve malicious content to legitimate users by poisoning shared cache entries Cloudflare's CDN infrastructure was 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. Mitigation: We strongly recommend Pingora users to upgrade to Pingora v0.8.0 or higher, which removes the insecure default cache key implementation. Users must now explicitly implement their own callback that includes appropriate factors such as Host header, origin server HTTP scheme, and other attributes their cache should vary on. Pingora users on previous versions may also remove any of their default CacheKey usage and implement their own that should at minimum include the host header / authority and upstream peer’s HTTP scheme.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencePingora's default CacheKey implementation uses only the URI path for cache keys, ignoring the Host header/authority. This allows attackers to poison caches by injecting malicious responses that then get served to legitimate users requesting different hosts.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 0.8.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Pingora versionLocate the Pingora library/binary in your environment and retrieve its version number (e.g., via package manager, dependency file, or binary version flag).Affected if The installed version is lower than 0.8.0.
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Confirm caching is enabledInspect your Pingora configuration files or code for CacheKey or cache-related settings. Look for any caching module or proxy_cache directives being used.Affected if Caching is enabled and a default CacheKey implementation is in use.
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Inspect the CacheKey implementationExamine the code or configuration that defines the cache key logic. Check whether the implementation explicitly includes the Host header or authority in the cache key, or whether it relies on the default behavior that uses only the URI path.Affected if The CacheKey uses only the URI path without including the Host header or upstream HTTP scheme.
You are affected if you are running Pingora versions below 0.8.0 with caching enabled and using the default CacheKey that does not incorporate the Host header or authority into the cache key.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped0.8.0
Upgrade to Pingora v0.8.0+ which removes the insecure default, or implement a custom CacheKey callback that includes the Host header and upstream HTTP scheme.
Pingora v0.8.0 or higher
- Identify all code using Pingora's default CacheKey implementation
- Upgrade Pingora dependency to version 0.8.0 or higher
- Remove any reliance on the removed default CacheKey implementation
- Implement a custom CacheKey callback that includes the Host header (authority) and upstream peer's HTTP scheme
- Add any additional cache-varying attributes specific to your deployment (e.g., tenant identifiers)
- Test cache behavior to verify proper cache key isolation between different hosts/tenants
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-2836 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-2836 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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- Version or environment caveats, and links to real fixes
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