CVE-2026-2836Network attack vector

Cross-origin cache poisoning via path-only keys

Published Mar 4, 2026 · Updated Mar 4, 2026

Cache poisoning in Cloudflare Pingora before 0.8.0 allows remote attackers to serve cross-origin responses through shared caches. The default CacheKey implementation uses only the URI path, omitting the host authority, upstream scheme, and other request attributes needed to separate cache entries. Exposure requires the experimental caching feature, its default key implementation, and shared caching across hosts; successful poisoning can disclose cross-tenant content or serve attacker-selected content.

CVSS severity8.4
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cache poisoning in Cloudflare Pingora before 0.8.0 allows remote attackers to serve cross-origin responses through shared caches. The default CacheKey implementation uses only the URI path, omitting the host authority, upstream scheme, and other request attributes needed to separate cache entries. Exposure requires the experimental caching feature, its default key implementation, and shared caching across hosts; successful poisoning can disclose cross-tenant content or serve attacker-selected content.

The record

CVE
CVE-2026-2836
Published
Mar 4, 2026
Updated
Mar 4, 2026
Vendor
Cloudflare
Product
Pingora
Classifications
CWE-345, 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

8.4Cloudflare, Inc.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
8.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-345Insufficient Verification of Data Authenticity
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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