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Fencer Vulns
low 3.1

CVE-2026-39388 json

OpenBao's Certificate Authentication Allows Token Renewal With Different Certificate

published 2026-04-21 6 mo ago modified 2026-09-10 1 mo ago also BIT-openbao-2026-39388 , EUVD-2026-24029 , GHSA-7ccv-rp6m-rffr , GO-2026-5213

cvss
3.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits
0
none known

Summary

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, OpenBao's Certificate authentication method, when a token renewal is requested and `disable_binding=true` is set, attempts to verify the current request's presented mTLS certificate matches the original. Token renewals for other authentication methods do not require any supplied login information. Due to incorrect matching, the certificate authentication method would allow renewal of tokens for which the attacker had a sibling certificate+key signed by the same CA, but which did not necessarily match the original role or the originally supplied certificate. This implies an attacker could still authenticate to OpenBao in a similar scope, however, token renewal implies that an attacker may be able to extend the lifetime of dynamic leases held by the original token. This attack requires knowledge of either the original token or its accessor. This vulnerability is original from HashiCorp Vault. This is addressed in v2.5.3. As a workaround, ensure privileged roles are tightly scoped to single certificates.

Patch / fix

  • go github.com/openbao/openbao 0.0.0-20260420160924-abe84e1af4c3
  • bitnami openbao 2.5.3
  • openbao openbao 2.5.3
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • openbao openSUSE Tumbleweed 2.5.3-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:10594-1

  • openbao Alpine 3.24, Alpine 3.23 2.5.4-r0

alpine advisories ALPINE-CVE-2026-39388

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-2026-39388 updated cvss 4.2

OpenBao: OpenBao: Token renewal vulnerability via incorrect certificate matching in Certificate authentication.

  • Red Hat All currently supported Red Hat products
    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
6 mo ago

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 2.0 CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
GitHub 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N
CNA 4.0 2.0 CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
go github.com/openbao/openbao
<0.0.0-20260420160924-abe84e1af4c3
0.0.0-20260420160924-abe84e1af4c3
bitnami openbao
<2.5.3
2.5.3

Affected products

  • openbao openbao

Classification

Weakness
  • CWE-295 Improper Certificate Validation
  • CWE-863 Incorrect Authorization

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.