How severe is CVE-2026-71543?

No CVSS score has been assigned to CVE-2026-71543 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-71543?

CVE-2026-71543 affects the following packages: github.com/openbao/openbao (Go), github.com/openbao/openbao (Go). Ecosystems affected: Go.

How do I fix CVE-2026-71543?

Update github.com/openbao/openbao to 0.0.0-20260710001938-2d4ebafec5c5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-71543 is resolved across your whole dependency graph.

How do I detect CVE-2026-71543 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/openbao/openbao, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-71543 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-71543 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-71543 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-71543?

CVE-2026-71543 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 35th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-71543?

CVE-2026-71543 is classified as CWE-863 (CWE-863). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-71543 published, and has it been updated?

CVE-2026-71543 was published on September 21, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

CVE-2026-71543 — openbao

Fix: openbao/openbao@2d4ebaf

CVE-2026-71543 is a CWE-863 vulnerability in github.com/openbao/openbao. A fix is available for github.com/openbao/openbao — see the affected versions and patch details below.

OpenBao's Templated Policies Allow Privilege Escalation via Wildcard Characters

Also known asBIT-openbao-2026-71543GHSA-59w7-v8rr-pr4pGO-2026-6556

Published

Sep 21, 2026

Updated

Oct 21, 2026

Affected

2 pkgs

Patched

1 / 2

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs35th percentile — riskier than 35% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

🐹github.com/openbao/openbao🐹github.com/openbao/openbao

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Impact

ACL Policies

OpenBao supports "templated polices": Policies with placeholders that are replaced at evaluation time.

This allows you to write a single policy which e.g. grants user "alice" access to all entries in a key value engine prefixed with alice/ while granting "bob" access to bob/, "carol" access to carol/, etc.

If the data used in the template can be controlled by an attacker (e.g. your system allows the user to freely select their username) and "globbing" characters are considered valid ( e.g. * is a valid username) they will be able to escalate their privileges.

The problematic characters are *, + and /.

PKI Secrets Engine `allowed_uri_sans_template` and `allowed_domains` Polices

The PKI secrets engine allows you to limit the "common names" a user can requests a TLS certificate for. Similar to the ACL polices this allows you to restrict e.g. "alice" to alice.example.com, "bob" to bob.example.com, etc. via templates.

Again, if an attacker can control this data freely, they can trick the PKI engine into using e.g. the *.example.com glob effectively allowing them to issue certificates for any subdomain of example.com

The problematic character in this case is *.

SSH Secrets Engine `allowed_users` and `allowed_domains` Polices

The SSH secrets engine allows you to limit the "principal" a user can request as SSH certificate for. Similar to ACL and PKI, this allows templates.

The problematic character in this case is , as the template result is split at all commas and each entry will be allowed.

Am I affected?

You are affected, if a) you use a templated policy (ACL, PKI or SSH) and b) your users can modify data used by your template freely.

If you can guarantee that the data used in your templates will never contain the problematic characters, you are not affected. For example, if you use {{ identity.entity.id }} in your policy, you are not affected, because identity.entity.id is randomly generated by OpenBao.

Even with this vulnerability patched: Using user controllable data in your policies is probably not the best idea.

Patches

All three have been patched in OpenBao v2.6.0.

Affected Packages

2 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/openbao/openbao`	all versions	0.0.0-20260710001938-2d4ebafec5c5`go get github.com/openbao/openbao@v0.0.0-20260710001938-2d4ebafec5c5`
🐹Go	`github.com/openbao/openbao`	≥ 0.1.0	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/openbao/openbao, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/openbao/openbao to 0.0.0-20260710001938-2d4ebafec5c5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-71543 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

## Impact ### ACL Policies OpenBao supports "templated polices": Policies with placeholders that are replaced at evaluation time. This allows you to write a single policy which e.g. grants user "alice" access to all entries in a key value engine prefixed with `alice/` while granting "bob" access to `bob/`, "carol" access to `carol/`, etc. If the data used in the template can be controlled by an attacker (e.g. your system allows the user to freely select their username) and "globbing" characters are considered valid ( e.g. `*` is a valid username) they will be able to escalate their privile

O3 Security · Impact-Aware SCA

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