CVE-2026-42272Heimdall: Case-sensitive handling of URL-encoded slashes may lead to inconsistent path interpretation
- 7.8HighCVSS base score
- 0.40%Exploitation in 30 daysEPSS · top 66% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall handles URL-encoded slashes (%2F) in a case-sensitive manner, while percent-encoding is defined to be case-insensitive. As a result, the lowercase equivalent (%2f) is not recognized and therefore not processed as expected when allow_encoded_slashes is set to off (the default setting). This discrepancy can lead to differences in how request paths are interpreted by heimdall and upstream components, which may result in authorization bypass. This issue has been patched in version 0.17.14.
Timeline
ID reserved
By GitHub_M
- 12 days later
· 12 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | High7.8 | 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 |
| NVDNVD · Deferred | 4.0 | High7.8 | 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/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 |
- EPSS (exploitation in 30 days)
- 0.40% · top 66% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/dadrus/heimdallGHSA-43jv-5j4x-qv67 (opens in a new tab)
References
References4
- https://github.com/dadrus/heimdall/security/advisories/GHSA-43jv-5j4x-qv67 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/dadrus/heimdall/pull/3207 (opens in a new tab)x_refsource_MISC
- https://github.com/dadrus/heimdall/commit/8b0de6aba23a047cfee3081df878271bb17f4351 (opens in a new tab)x_refsource_MISC
- https://github.com/dadrus/heimdall/releases/tag/v0.17.14 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-28508 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-43jv-5j4x-qv67 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-42272)Record last updated .