CVE-2026-42273 json
Heimdall: Case-sensitive host matching may lead to policy bypass
published 2026-04-25 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-28509 , GHSA-72h4-mxfc-jx37 , GO-2026-5200
- cvss
- 7.8
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 23%
- public exploits
- 0
- none known
Summary
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall performs host matching in a case-sensitive manner, while HTTP hostnames are case-insensitive. This discrepancy can result in heimdall failing to match a rule for a request host that differs only in letter casing, potentially causing the request to be classified differently than intended. This issue has been patched in version 0.17.14.
Patch / fix
- go github.com/dadrus/heimdall 0.17.14
- dadrus heimdall 0.17.14
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
- github.com/dadrus/heimdall@3d05e56 commit
- github.com/dadrus/heimdall#3208 pull request
- github.com/dadrus/heimdall/releases/tag/v0.17.14 release
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.8 | 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 |
| CNA | 4.0 | 7.8 | 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 |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/dadrus/heimdall | <0.17.14 |
0.17.14 |
Affected products
- dadrus heimdall
Classification
References
-
github.com
/dadrus/heimdall/pull/3208
web, patch
-
github.com
/dadrus/heimdall/commit/3d05e56a9e7ef0355f17482b4322054af4e85943
web, patch
-
github.com
/dadrus/heimdall/security/advisories/GHSA-72h4-mxfc-jx37
web, advisory
-
github.com
/dadrus/heimdall/releases/tag/v0.17.14
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-42273
advisory
-
github.com
/dadrus/heimdall
package
Sources
- CVE List CVE-2026-42273
- GitHub Advisory GHSA-72h4-mxfc-jx37
- NVD CVE-2026-42273
- OSV GO-2026-5200
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.