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Fencer Vulns
critical 9.6

CVE-2026-33757 json

OpenBao lacks user confirmation for OIDC direct callback mode

published 2026-03-26 7 mo ago modified 2026-09-10 59 d ago also BIT-openbao-2026-33757 , EUVD-2026-16624 , GHSA-7q7g-x6vg-xpc3 , GO-2026-4860

cvss
9.6
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 36%
public exploits
0
none known

Summary

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.2, OpenBao does not prompt for user confirmation when logging in via JWT/OIDC and a role with `callback_mode` set to `direct`. This allows an attacker to start an authentication request and perform "remote phishing" by having the victim visit the URL and automatically log-in to the session of the attacker. Despite being based on the authorization code flow, the `direct` mode calls back directly to the API and allows an attacker to poll for an OpenBao token until it is issued. Version 2.5.2 includes an additional confirmation screen for `direct` type logins that requires manual user interaction in order to finish the authentication. This issue can be worked around either by removing any roles with `callback_mode=direct` or enforcing confirmation for every session on the token issuer side for the Client ID used by OpenBao.

Patch / fix

  • go github.com/openbao/openbao 0.0.0-20260325142553-e32103951925
  • bitnami openbao 2.5.2
  • openbao openbao 2.5.2
  • govulncheck-vulndb openSUSE Leap 15.6 0.0.20260326T203309-150000.1.155.2

suse advisories SUSE-SU-2026:1135-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • openbao openSUSE Tumbleweed 2.5.2-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:10438-1

  • openbao Alpine 3.24, Alpine 3.23 2.5.4-r0

alpine advisories ALPINE-CVE-2026-33757

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2026-33757 updated cvss 9.6

OpenBao: lack of user confirmation for OpenBao OIDC direct callback mode

  • Red Hat Cryostat 4 cryostat/cryostat-storage-rhel9
    not affected: component 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
total
Assessed
7 mo ago

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
CISA ADP 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
GitHub 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
NVD 3.1 8.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L
OSV 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L

Affected packages

ecosystem package affected fixed in
go github.com/openbao/openbao
<0.0.0-20260325142553-e32103951925
0.0.0-20260325142553-e32103951925
bitnami openbao
<2.5.2
2.5.2

Affected products

  • openbao openbao
  • Red Hat Cryostat 4

Classification

Weakness

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.