CVE-2026-90711Network attack vectorHinoki check available

Unauthenticated IP spoofing via mapped-IPv6 subnet misparsing

Published Sep 15, 2026 · Updated Sep 15, 2026

Improper subnet validation in jshttp proxy-addr 1.1.0 through 2.0.7 allows remote attackers to spoof client IP addresses. The trust compiler accepts an IPv4-mapped IPv6 CIDR with an IPv4-sized prefix and interprets it as trusting every IPv4 address, after which X-Forwarded-For controls the returned client address. Reachability requires an application configured with that malformed trust subnet; affected controls include IP allowlists, rate limits, geolocation, and audit logs.

CVSS severityUnavailable
Unscored
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper subnet validation in jshttp proxy-addr 1.1.0 through 2.0.7 allows remote attackers to spoof client IP addresses. The trust compiler accepts an IPv4-mapped IPv6 CIDR with an IPv4-sized prefix and interprets it as trusting every IPv4 address, after which X-Forwarded-For controls the returned client address. Reachability requires an application configured with that malformed trust subnet; affected controls include IP allowlists, rate limits, geolocation, and audit logs.

The record

CVE
CVE-2026-90711
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
jshttp
Product
proxy-addr
Classifications
T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=1.1.0 <2.0.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

jshttp · proxy-addrversion=1.1.0 <2.0.8

Published CVSS scores

No CVSS assessment is available in this record.

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 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 exploitUnconfirmed

Weakness, pattern, technique

T1036Masquerading

Public exploit references

No public exploit references are available in this record.

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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