{"id":"CVE-2026-82562","title":"### Summary\n\n\n\nWhen `qs.parse` is called with `comma: true` and `throwOnLimitExceeded: true`, a comma-separated value under a bracket-push key (`a[]=1,2,3,4`) is split into an array without being compared against `arrayLimit`, while the …","summary":"### Summary\n\n\n\nWhen `qs.parse` is called with `comma: true` and `throwOnLimitExceeded: true`, a comma-separated value under a bracket-push key (`a[]=1,2,3,4`) is split into an array without being compared against `arrayLimit`, while the …","severity":"low","cvss":3.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-770"],"published":"2026-08-30","updated":"2026-08-30","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-82562","references":[{"url":"https://github.com/ljharb/qs/commit/8859c37470e11b42b547b275e4e9bd0bc8cc5464","label":"7ffcee3d-2c14-4c3e-b844-86c6a321a158"},{"url":"https://github.com/ljharb/qs/security/advisories/GHSA-w7fw-mjwx-w883","label":"7ffcee3d-2c14-4c3e-b844-86c6a321a158"},{"url":"https://github.com/ljharb/qs/security/advisories/GHSA-x5fp-wj9c-mxmx","label":"7ffcee3d-2c14-4c3e-b844-86c6a321a158"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-82562.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-82562"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2525939"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-82562"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-82562"},{"url":"https://access.redhat.com/errata/RHSA-2026:60866"},{"url":"https://access.redhat.com/errata/RHSA-2026:62544"},{"url":"https://access.redhat.com/errata/RHSA-2026:63164"},{"url":"https://access.redhat.com/errata/RHSA-2026:68754"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00317,"epssPercentile":0.24887,"ingestedAt":"2026-08-30T14:53:42.577Z","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["cost_management_on_premise","cryostat 4","gatekeeper 3","migration_toolkit_for_applications 8","migration_toolkit_for_containers","multicluster_engine_for_kubernetes","node_healthcheck_operator","openshift_lightspeed","openshift_pipelines","openshift_serverless","openshift_service_mesh 3","3scale_api_management_platform 2","advanced_cluster_management_for_kubernetes 2","advanced_cluster_security 4","amq_broker 7","ansible_automation_platform 2","build_of_apache_camel_for_spring_boot 4","build_of_podman_desktop","ceph_storage 4","ceph_storage 6","ceph_storage 7","ceph_storage 8","ceph_storage 9","connectivity_link 1","data_grid 8","developer_hub","discovery 2","enterprise_linux 10","enterprise_linux 7","enterprise_linux 8","enterprise_linux 9","enterprise_linux_ai_rhel_ai 3","fuse 7","hardened_images","jboss_enterprise_application_platform 7","openshift_ai_rhoai","openshift_container_platform 4","openshift_data_foundation 4","openshift_dev_spaces","openshift_gitops"],"patched":["hardened_images"],"slug":"CVE-2026-82562","body":"## Overview\n\n### Summary\n\n\n\nWhen `qs.parse` is called with `comma: true` and `throwOnLimitExceeded: true`, a comma-separated value under a bracket-push key (`a[]=1,2,3,4`) is split into an array without being compared against `arrayLimit`, while the same value under a flat key (`a=1,2,3,4`), an indexed key (`a[0]=`), a nested key (`a[b]=`), or a dotted key (`a.b=` with `allowDots`) throws the documented `RangeError`. A single parameter such as `a[]=1,2,2,...` therefore produces an inner array of arbitrary length even though the caller opted into the hard limit. This is the `[]=` key form that the fix for CVE-2026-2391 (qs 6.14.2) did not cover.\n\n\n\n### Details\n\n\n\nIn `lib/parse.js`, a comma-separated value under a `[]=` key is split and then wrapped as a single nested element (`val = [val]`, so that each `a[]=x,y` group counts as one element of the outer array). The `arrayLimit` check that 6.14.2 added for comma values runs after that wrap, so for `[]=` parts it only ever saw the wrapper of length 1. 6.15.3 added a pre-split comma count so that an oversized value throws before it is allocated, but gated it on an `isFlatArrayValue` flag that `parseValues` set to `false` for any part containing `[]=`, and did not pass it for object-valued input, so the gap remained.\n\n\n\n#### PoC\n\n\n\n```js\n\n\n\nvar qs = require('qs');\n\n\n\nvar options = { comma: true, arrayLimit: 3, throwOnLimitExceeded: true };\n\n\n\nqs.parse('a=1,2,3,4', options);   // RangeError: Array limit exceeded. Only 3 elements allowed in an array.\n\n\n\nqs.parse('a[]=1,2,3,4', options); // { a: [ [ '1', '2', '3', '4' ] ] }  (no throw)\n\n\n\nqs.parse('a[]=' + '1,'.repeat(1000000) + '1', { comma: true, arrayLimit: 20, throwOnLimitExceeded: true });\n\n\n\n// no throw; a 1,000,001-element inner array is allocated\n\n\n\n```\n\n\n\n#### Fix\n\n\n\n`lib/parse.js`, applied in 8859c37 on `main` and released as v6.16.0: the `isFlatArrayValue` gate is removed, so every comma-split value is counted against `arrayLimit` before splitting regardless of key form. An in-limit group under `a[]=` still counts as one element of the outer array, and the default (`throwOnLimitExceeded: false`) path is unchanged.\n\n\n\n### Affected versions\n\n\n\n`>=6.14.2 <6.16.0`, fixed in v6.16.0.\n\n\n\nv6.14.2 introduced `arrayLimit` enforcement for comma values (the fix for CVE-2026-2391) but only for values not under a `[]=` key, and every release from v6.14.2 through v6.15.3 has the same gap. v6.14.0 and v6.14.1, where `throwOnLimitExceeded` exists but does not apply to any comma form, are covered by CVE-2026-2391 rather than this record. Earlier lines (6.7.x through 6.13.x) have `comma` but no `throwOnLimitExceeded`, so there is no hard cap on any comma path to bypass; releases before 6.7.0 have no `comma` option.\n\n\n\n### Impact\n\n\n\nAn unauthenticated attacker who can reach an application that parses untrusted query strings or urlencoded bodies with both `comma: true` and `throwOnLimitExceeded: true` (both non-default) can bypass the configured limit with a single `a[]=` parameter and force the parser to allocate an array proportional to the request size. The cost is strictly linear in the attacker-supplied bytes (about 0.1 microseconds and 6 to 7 retained bytes per input byte; the same out-of-memory threshold as the documented default `throwOnLimitExceeded: false` path), so a transport-layer request or body size limit bounds it completely (and node's default maximum HTTP header size of 16 KB already bounds the request line, so multi-megabyte payloads need a body parser). The impact is that an opt-in hard limit fails open on one key spelling, not unbounded allocation from a small input.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:60866** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:60866)\n- **RHSA-2026:62544** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:62544)\n- **RHSA-2026:63164** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63164)\n- **Red Hat VEX** · Low · affected: Cost Management On Premise, Cryostat 4, Gatekeeper 3, Migration Toolkit for Applications 8, Migration Toolkit for Containers, Multicluster Engine for Kubernetes, … · no fix planned: Node HealthCheck Operator, OpenShift Service Mesh 3, Red Hat 3scale API Management Platform 2, Red Hat Advanced Cluster Management for Kubernetes 2, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-82562.json)\n- **RHSA-2026:68754** · Red Hat · fixed in: Red Hat OpenShift Dev Spaces 3.30 · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68754)","depth":"sunlit","depthScore":20,"depthScoreParts":{"impact":20.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}