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Fencer Vulns
medium 6.1

CVE-2026-83589 json

Oauth-proxy: open redirect via /\ and /\t bypass in post-login redirect

published 2026-10-01 39 d ago modified 2026-10-30 10 d ago also EUVD-2026-90589

cvss
6.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

A flaw was found in oauth-proxy. The application fails to properly validate the destination redirect parameter (`rd`) during post-login redirection. A remote attacker can exploit this vulnerability by enticing a user to follow a specially crafted link, resulting in the user being redirected to an arbitrary external website after authenticating. This open redirect can be leveraged to conduct phishing attacks or credential theft.

Patch / fix

  • Red Hat Red Hat OpenShift Container Platform 4.12 1792974337
  • Red Hat Red Hat OpenShift Container Platform 4.14 1791837363
  • Red Hat Red Hat OpenShift Container Platform 4.15 1791632336
  • Red Hat Red Hat OpenShift Container Platform 4.16 1792878232
  • Red Hat Red Hat OpenShift Container Platform 4.18 1790882320
  • Red Hat Red Hat OpenShift Container Platform 4.19 1790807096
  • Red Hat Red Hat OpenShift Container Platform 4.20 1790704224
  • Red Hat Red Hat OpenShift Container Platform 4.21 1790706478
  • Red Hat Red Hat OpenShift Container Platform 4.22 1790724885

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-83589 updated cvss 6.1

oauth-proxy: Open Redirect via /\ and /\t Bypass in Post-Login Redirect

  • Red Hat OpenShift Container Platform 4.12 openshift4/ose-oauth-proxy 1792974337
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:90274
  • Red Hat OpenShift Container Platform 4.14 openshift4/ose-oauth-proxy 1791837363
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:82785
  • Red Hat OpenShift Container Platform 4.15 openshift4/ose-oauth-proxy-rhel9 1791632336
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:82813
  • Red Hat OpenShift Container Platform 4.16 openshift4/ose-oauth-proxy-rhel9 1792878232
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:89715
  • Red Hat OpenShift Container Platform 4.18 openshift4/ose-oauth-proxy-rhel9 1790882320
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:79039
  • Red Hat OpenShift Container Platform 4.19 openshift4/ose-oauth-proxy-rhel9 1790807096
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:79169
  • Red Hat OpenShift Container Platform 4.20 openshift4/ose-oauth-proxy-rhel9 1790704224
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:74380
  • Red Hat OpenShift Container Platform 4.21 openshift4/ose-oauth-proxy-rhel9 1790706478
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:74383
show 2 more
  • Red Hat OpenShift Container Platform 4.22 openshift4/ose-oauth-proxy-rhel9 1790724885
    fixed: vendor fix “Red Hat has not identified any known mitigations for this issue. Customers are advised to apply the available security update when released.” RHSA-2026:74429
  • Red Hat OpenShift Container Platform 4.12 openshift4/ose-cli 1792978815, openshift4/ose-pod 1792975145, openshift4/ose-etcd 1792974936, openshift4/ose-tests 1792891850, openshift4/ose-console 1792976642, openshift4/ose-coredns 1792977034, +183 more Red Hat OpenShift Container Platform 4.14 openshift4/ose-cli 1791838793, openshift4/ose-pod 1791842699, openshift4/ose-tests 1791781968, openshift4/ose-console 1791842061, openshift4/ose-coredns 1791842976, openshift4/ose-deployer 1791843620, +189 more Red Hat OpenShift Container Platform 4.15 openshift4/ose-cli 1791878476, openshift4/ose-tests 1791889482, openshift4/ose-console 1791836468, openshift4/ose-deployer 1791888334, openshift4/ose-installer 1791889788, openshift4/ose-pod-rhel9 1791639781, +184 more Red Hat OpenShift Container Platform 4.16 openshift4/ose-cli-rhel9 1792881772, openshift4/ose-pod-rhel9 1792881268, openshift4/ose-sdn-rhel9 1792891515, openshift4/ose-etcd-rhel9 1792884751, openshift4/ose-tests-rhel9 1792892635, openshift4/ose-tools-rhel9 1792881835, +182 more Red Hat OpenShift Container Platform 4.18 openshift4/frr-rhel9 1790826545, openshift4/ose-cli-rhel9 1790882345, openshift4/ose-pod-rhel9 1790853956, openshift4/ose-etcd-rhel9 1791320060, openshift4/ose-tests-rhel9 1791373456, openshift4/ose-tools-rhel9 1791372072, +180 more Red Hat OpenShift Container Platform 4.19 openshift4/frr-rhel9 1790806908, openshift4/ose-cli-rhel9 1790807603, openshift4/ose-pod-rhel9 1790807770, openshift4/ose-etcd-rhel9 1790807722, openshift4/ose-tests-rhel9 1791357102, openshift4/ose-tools-rhel9 1791355810, +180 more
    +4 more products
    Red Hat OpenShift Container Platform 4.20 openshift4/frr-rhel9 1790702743, openshift4/ose-cli-rhel9 1790701502, openshift4/ose-pod-rhel9 1790705159, openshift4/ose-etcd-rhel9 1790703604, openshift4/ose-tests-rhel9 1790707913, openshift4/ose-tools-rhel9 1790703780, +182 more Red Hat OpenShift Container Platform 4.21 openshift4/frr-rhel9 1790703737, openshift4/ose-cli-rhel9 1790702464, openshift4/ose-pod-rhel9 1790704469, openshift4/ose-etcd-rhel9 1790706697, openshift4/ose-tests-rhel9 1790708632, openshift4/ose-tools-rhel9 1790704750, +181 more Red Hat OpenShift Container Platform 4.22 openshift4/frr-rhel9 1790741595, openshift4/ose-cli-rhel9 1790712167, openshift4/ose-pod-rhel9 1790723524, openshift4/ose-etcd-rhel9 1790712437, openshift4/ose-tests-rhel9 1790726162, openshift4/ose-tools-rhel9 1790712958, +182 more Red Hat OpenShift Container Platform 5 openshift5/ose-oauth-proxy-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
38 d ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected products

  • Red Hat Red Hat OpenShift Container Platform 4.12
  • Red Hat Red Hat OpenShift Container Platform 4.14
  • Red Hat Red Hat OpenShift Container Platform 4.15
  • Red Hat Red Hat OpenShift Container Platform 4.16
  • Red Hat Red Hat OpenShift Container Platform 4.18
  • Red Hat Red Hat OpenShift Container Platform 4.19
  • Red Hat Red Hat OpenShift Container Platform 4.20
  • Red Hat Red Hat OpenShift Container Platform 4.21
  • Red Hat Red Hat OpenShift Container Platform 4.22
  • Red Hat Red Hat OpenShift Container Platform 5

Classification

Weakness
  • CWE-601 URL Redirection to Untrusted Site

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.