CVE-2026-42274CWE-35CWE-436

Heimdall: Authorization bypass via path normalization mismatch

High · published May 8, 2026

CVSS v4.0
7.8
EPSS
1%
Percentile
44.6
In the wild
Unconfirmed
What it is

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall performs rule matching on the raw (non-normalized) request path, while downstream components may normalize dot-segments according to RFC 3986, Section 6.2.2.3. This discrepancy can result in heimdall authorizing a request for one path (e.g., /user/../admin, or URL-encoded variants such as /user/%2e%2e/admin or /user/%2e%2e%2fadmin. The latter would require the allow_encoded_slashes option to be set to on or no_decode.) while the downstream ultimately processes a different, normalized path (/admin). This issue has been patched in version 0.17.14.

The record
Technical detail
CVSS v4.0
7.8 · HIGH
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
EPSS
0.00540 · 44.6th percentile
Weaknesses
CWE-35 · Path Traversal: '.../...//'; CWE-436 · Interpretation Conflict
Published
2026-05-08T03:43Z
EPSS history
Timeline
  • 08 MAY 03:43Z
    Heimdall: Authorization bypass via path normalization mismatch
    cvelistv5