--- id: CVE-2026-40542 title: >- Missing critical step in authentication in Apache HttpClient 5.6 allows an attacker to cause the client to accept SCRAM-SHA-256 authentication without proper mutual authentication verification summary: >- Missing critical step in authentication in Apache HttpClient 5.6 allows an attacker to cause the client to accept SCRAM-SHA-256 authentication without proper mutual authentication verification. Users are recommended to upgrade to version… severity: high cvss: 7.3 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L' cwe: - CWE-304 - CWE-325 vendor: apache product: httpclient affected: - httpclient = 5.6 patched: - openshift_developer_tools_and_services 4.12 - openshift_developer_tools_and_services 4.13 - openshift_developer_tools_and_services 4.14 - openshift_developer_tools_and_services 4.15 - openshift_developer_tools_and_services 4.16 - openshift_developer_tools_and_services 4.17 - openshift_developer_tools_and_services 4.18 - openshift_developer_tools_and_services 4.19 - openshift_developer_tools_and_services 4.20 - openshift_developer_tools_and_services 4.21 - openshift_developer_tools_and_services 4.22 published: '2026-04-22' updated: '2026-09-09' sourceUpdated: '2026-09-09T13:19:50.873' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-40542' references: - url: 'https://lists.apache.org/thread/tfmgv86xr0z1y096vs3z0y315t1v3o97' label: security@apache.org - url: 'http://www.openwall.com/lists/oss-security/2026/04/22/5' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://access.redhat.com/errata/RHSA-2026:60239' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60246' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60247' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60248' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60249' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60250' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60251' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60252' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60254' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60256' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60259' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/security/cve/CVE-2026-40542' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2460518' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40542.json label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://www.cve.org/CVERecord?id=CVE-2026-40542' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-40542' tags: - nvd - cve.org - csaf - vex - red-hat ssvc: exploitation: none automatable: 'yes' technicalImpact: partial timestamp: '2026-04-22T14:14:52.319783Z' epss: 0.00702 epssPercentile: 0.51158 ingestedAt: '2026-08-26T16:46:31.105Z' --- ## Overview Missing critical step in authentication in Apache HttpClient 5.6 allows an attacker to cause the client to accept SCRAM-SHA-256 authentication without proper mutual authentication verification. Users are recommended to upgrade to version 5.6.1, which fixes this issue. ## Affected - `httpclient = 5.6` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Vendor advisories - **RHSA-2026:60247** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.12 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60247) - **RHSA-2026:60249** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.13 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60249) - **RHSA-2026:60248** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.14 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60248) - **RHSA-2026:60239** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.15 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60239) - **RHSA-2026:60251** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.16 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60251) - **RHSA-2026:60246** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.17 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60246) - **RHSA-2026:60250** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.18 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60250) - **RHSA-2026:60252** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.19 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60252) - **RHSA-2026:60259** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.20 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60259) - **RHSA-2026:60254** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.21 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60254) - **RHSA-2026:60256** · Red Hat · fixed in: OpenShift Developer Tools and Services 4.22 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60256) - **Red Hat VEX** · Important · affected: OpenShift Developer Tools and Services · no fix planned: OpenShift Developer Tools and Services · updated 2026-09-08 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40542.json)