CVE-2026-2835Public exploitNetwork attack vector

Request smuggling via inconsistent HTTP/1 message framing

Published Mar 4, 2026 · Updated Mar 4, 2026

HTTP request smuggling in Cloudflare Pingora before 0.8.0 allows remote attackers to inject backend requests through an ingress proxy. The HTTP/1 parser treats some HTTP/1.0 request bodies as close-delimited and recognizes only a single exact Transfer-Encoding value, causing Pingora and a backend to disagree about request boundaries. Exploitation requires a standalone ingress deployment in front of a backend that accepts the conflicting framing and enables ACL bypass, cache poisoning, or cross-user session theft.

CVSS severity9.3
Critical
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP request smuggling in Cloudflare Pingora before 0.8.0 allows remote attackers to inject backend requests through an ingress proxy. The HTTP/1 parser treats some HTTP/1.0 request bodies as close-delimited and recognizes only a single exact Transfer-Encoding value, causing Pingora and a backend to disagree about request boundaries. Exploitation requires a standalone ingress deployment in front of a backend that accepts the conflicting framing and enables ACL bypass, cache poisoning, or cross-user session theft.

The record

CVE
CVE-2026-2835
Published
Mar 4, 2026
Updated
Mar 4, 2026
Vendor
Cloudflare
Product
Pingora
Classifications
CWE-444, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Cloudflare · Pingoraversion=0 <0.8.0

Published CVSS scores

9.3GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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