openbao: Improper Authentication
CVE-2026-126310 is a high-severity improper authentication vulnerability in openbao, with a CVSS 3.1 base score of 8.7 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 2.6.5, 2.7.2 as the first without the flaw, so updating openbao to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update openbao to 2.6.5 or 2.7.2, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Openbao | openbao | before 2.6.5; 2.7.0 up to, but not including, 2.7.2 | 2.6.5, 2.7.2 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.0 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 8.7 | High | CNA (vulncheck.com) |
Official description
OpenBao before 2.6.5 and 2.7.2 contains an authentication bypass vulnerability that allows unauthenticated callers to obtain OIDC ID tokens by abusing public clients with client_credentials enabled. Attackers who know a public client's client_id can request tokens from the identity/oidc/provider/<name>/token endpoint to impersonate the client without any secret.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
References
Other references
Other vulnerabilities in openbao
- 7.1 High severity
- 7.1 High severity
- 9.2 Critical severity
- 7.5 High severity
- 7.1 High severity
- 7.5 High severity
Recent Improper Authentication vulnerabilities
- 8.1 High severity
- 8.3 High severity
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
- 8.1 High severity
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