# CVE-2026-128100: Vault vulnerable to ACL deny bypass via case-variant auth method user and group names

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

Vault Community Edition and Vault Enterprise did not apply explicit ACL policy deny rules to letter case variants of user and group names in auth methods that treat these names as case-insensitive. This may allow an authenticated user with delegated permissions to modify a protected user or group, potentially leading to privilege escalation. This vulnerability (CVE-2026-128100) is fixed in Vault Community Edition 2.2.2 and Vault Enterprise 2.2.2, 1.21.14, and 1.19.25.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- HashiCorp / Vault: ≥ 0.10.0; < 2.2.2 (affected, semver). Source: CNA: HashiCorp; platforms: 64 bit, 32 bit, x86, ARM, MacOS, Windows, Linux
- HashiCorp / Vault Enterprise: ≥ 0.10.0; < 2.2.2 (affected, semver); unaffected at 1.19.25; affected at 1.20.0; unaffected at 1.21.14; affected at 2.0.0. Source: CNA: HashiCorp; platforms: 64 bit, 32 bit, x86, ARM, MacOS, Windows, Linux

## Severity and prioritization

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H; source: CNA: HashiCorp

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-178

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://discuss.hashicorp.com/t/hcsec-2026-58-vault-vulnerable-to-acl-deny-bypass-via-case-variant-auth-method-user-and-group-names/78256 (CNA: HashiCorp)

## Provenance

- CNA: HashiCorp: https://www.cve.org/CVERecord?id=CVE-2026-128100; retrieved 2026-11-13; source updated 2026-11-13

Revision: 39ef884c0f986cf9ccac0efce33d9842b5bad554afd45f1a556196a9a0df2770

Canonical: https://y2.dev/cve/CVE-2026-128100

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