CVE-2026-2833
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 · uneditedAn HTTP request smuggling vulnerability (CWE-444) was found in Pingora's handling of HTTP/1.1 connection upgrades. The issue occurs when a Pingora proxy reads a request containing an Upgrade header, causing the proxy to pass through the rest of the bytes on the connection to a backend before the backend has accepted the upgrade. An attacker can thus directly forward a malicious payload after a request with an Upgrade header to that backend in a way that may be interpreted as a subsequent request header, bypassing proxy-level security controls and enabling cross-user session hijacking. Impact This vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to: * Bypass proxy-level ACL controls and WAF logic * Poison caches and upstream connections, causing subsequent requests from legitimate users to receive responses intended for smuggled requests * Perform cross-user attacks by hijacking sessions or smuggling requests that appear to originate from the trusted proxy IP Cloudflare's CDN infrastructure was not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode. Mitigation: Pingora users should upgrade to Pingora v0.8.0 or higher As a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.
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 HTTP/1.1 upgrade handling has a request smuggling vulnerability where the proxy forwards additional bytes to the backend before the upgrade is accepted, allowing attackers to append malicious payloads that get interpreted as subsequent request headers by the backend, bypassing proxy ACLs and WAF controls.
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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 versionCheck the installed or deployed version of the Pingora proxy (e.g., via binary version flag, dependency lock file, or runtime introspection if available)Affected if The installed version is lower than 0.8.0
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Locate Pingora configurationFind the main Pingora configuration file or deployment manifest that controls proxy behaviorAffected if No configuration file exists or upgrade handling cannot be verified
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Verify HTTP/1.1 upgrade handling is enabledInspect the Pingora configuration for any directives, flags, or modules related to HTTP/1.1 upgrade handling (such as 'upgrade', 'websocket', or similar proxy features)Affected if HTTP/1.1 upgrade handling is explicitly enabled in the configuration
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Confirm upgrade requests are routed through the proxyReview access logs, proxy routing rules, or upstream backend configurations to determine if client requests with Upgrade headers are being forwarded to backendsAffected if Requests containing Upgrade headers are being proxied to backends
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Check for upstream backend configurationsExamine the proxy upstream definitions to see which backend services are configured and whether they accept HTTP/1.1 upgradesAffected if The proxy is configured to forward requests to backends that handle HTTP/1.1 upgrades
You are affected if Pingora version is below 0.8.0 AND HTTP/1.1 upgrade handling is enabled and actively proxying Upgrade requests to backends.
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 or higher to obtain the patch, or implement a temporary workaround that rejects requests containing Upgrade headers in request filter logic.
Pingora v0.8.0
- Identify the current Pingora version in use by checking the deployed binary or library version
- Upgrade Pingora to version 0.8.0 or higher using the project's recommended upgrade procedure
- Verify the upgrade was successful by confirming the installed version is >= 0.8.0
- Test HTTP/1.1 upgrade functionality after the upgrade to ensure legitimate upgrades still work correctly
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-2833 — 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-2026-2833 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
No notes yet
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- Version or environment caveats, and links to real fixes
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