CVE-2026-90711

criticalpriority · track · 0EPSS 0.003 · 18 %ileDEFRUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.26% (18th) EPSS
CVSS 9.1 · critical
Is it mine?
6 products
Check your exposure
Who says so?
3 sources
cert_bund · osv · certfr

EPSS · scored 2026-10-27

proxy-addr is a Node.js module that determines a request's client address behind trusted reverse proxies, and it backs Express req.ip and req.ips. In versions 1.1.0 through 2.0.7, a trust subnet written in IPv4-mapped IPv6 notation with an IPv4-sized prefix, such as ::ffff:10.0.0.0/8 instead of the correct ::ffff:10.0.0.0/104, is accepted without error but trusts every IPv4 address on the internet rather than the block it names. Because the socket peer then becomes trusted at hop 0, any unauthenticated client can supply an arbitrary X-Forwarded-For header and control the address the application reads, which defeats IP-based access control, rate limiting, geolocation, and audit logging. This is a fail-open regression introduced in version 1.1.0. The issue is fixed in proxy-addr 2.0.8, and users should upgrade to 2.0.8 or later. As a workaround, ensure any IPv4-mapped IPv6 trust subnet uses a prefix length of at least 97, or express the range in plain IPv4 notation.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.1
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.3–9.1

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondaryexploitability 3.9 · impact 5.2
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · OSV
v3.18.3highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (6)

Products and version ranges known to be affected.

05

advisories (4)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-4111Red Hat Ansible Automation Platform: Mehrere SchwachstellenDeutsch2026-10-21csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Red Hat Ansible Automation Platform ausnutzen, um beliebigen Code mit Benutzer- oder Anwendungsrechten auszuführen, gültige kryptografische Token zu fälschen, die Authentifizierung zu umgehen, erweiterte Rechte zu erlangen, Denial-of-Service-Zustände auszulösen sowie Daten zu manipulieren oder offenzulegen.

  • GHSA-jqcg-44mw-7w3hproxy-addr vulnerable to IP spoofing via IPv4-mapped IPv6 trust subnet2026-10-05ghsa · osvUS

    ### Impact `proxy-addr` determines which network hops are trusted proxies so that `X-Forwarded-For` can be believed. When an application configures a trust subnet as an IPv4-mapped IPv6 address with a short prefix, such as `::ffff:10.0.0.0/8` (the correct spelling is `::ffff:10.0.0.0/104`), the subnet compiles with all-zero leading bits and matches every IPv4 address instead of the block it names. The same happens for any IPv6 trust subnet with zero leading bits, such as `::/1`. Every unauthenticated client is then trusted as a proxy at hop 0, so `proxyaddr(req, trust)`, and therefore `req.ip` and `req.ips` in Express, returns whatever the client sends in `X-Forwarded-For`. This defeats IP-based access control, rate limiting, geolocation, and audit logging. The misconfiguration compiles without any error, and the same block written correctly behaves correctly, so the difference is not visible from the configuration. ### Patches Upgrade to `proxy-addr` 2.0.8. An IPv4 address now matches an IPv6 trust subnet only when that subnet is a genuine IPv4-mapped subnet whose prefix covers the mapped marker. ### Workarounds Write IPv4 trust subnets in plain IPv4 notation (for example `10.0.0.0/8`). If IPv4-mapped IPv6 notation is required, use the full form so the prefix covers the mapped marker (for example `::ffff:10.0.0.0/104` for the `10.0.0.0/8` block).

  • CERTFR-2026-AVI-1378Multiples vulnérabilités dans les produits IBMFrançais2026-10-23vendor · certfrFR
  • CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
06

sources

Which sources assert this record, and when.

published 2026-09-15modified 2026-09-16
07

references (2) nvd

External citations — patches, advisories, analysis.

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