--- id: CVE-2026-104874 title: Multidict is an implementation of a multidict data structure summary: >- Multidict is an implementation of a multidict data structure. From 6.7.0 until 6.9.1, the C extension's items-view reflected union operation, operand | d.items(), in multidict_itemsview_or2_impl and subtraction operation, d.items() - ope… severity: medium cvss: 5.3 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L' cwe: - CWE-401 - CWE-911 vendor: aio-libs product: multidict affected: - 'multidict >= 6.7.0, < 6.9.1' patched: - multidict 6.9.1 published: '2026-10-02' updated: '2026-10-06' sourceUpdated: '2026-10-06T16:08:43.180' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-104874' references: - url: >- https://github.com/aio-libs/multidict/commit/350b4a07bf8ff851b6d7544e81b1c748bdc74c40 label: security-advisories@github.com - url: 'https://github.com/aio-libs/multidict/releases/tag/v6.9.1' label: security-advisories@github.com - url: >- https://github.com/aio-libs/multidict/security/advisories/GHSA-54p9-h82j-f925 label: security-advisories@github.com - url: >- https://github.com/aio-libs/multidict/security/advisories/GHSA-54p9-h82j-f925 label: 134c704f-9b21-4f2e-91b3-4a467353bcc0 - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-104874.json - url: 'https://access.redhat.com/security/cve/CVE-2026-104874' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2545386' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-104874' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-104874' - url: 'https://github.com/advisories/GHSA-54p9-h82j-f925' - url: 'https://github.com/aio-libs/multidict' - url: 'https://access.redhat.com/errata/RHSA-2026:82415' - url: 'https://access.redhat.com/errata/RHSA-2026:82368' - url: 'https://access.redhat.com/errata/RHSA-2026:82061' - url: 'https://access.redhat.com/errata/RHSA-2026:82059' - url: 'https://access.redhat.com/errata/RHSA-2026:82371' - url: 'https://access.redhat.com/errata/RHSA-2026:83116' - url: 'https://access.redhat.com/errata/RHSA-2026:83112' - url: 'https://access.redhat.com/errata/RHSA-2026:83120' - url: 'https://access.redhat.com/errata/RHSA-2026:83121' - url: 'https://access.redhat.com/errata/RHSA-2026:83114' - url: 'https://pypi.org/project/multidict' tags: - nvd - cve.org - exploit-available - csaf - vex - red-hat - ghsa - pip - osv epss: 0.00448 epssPercentile: 0.38775 aliases: - GHSA-54p9-h82j-f925 - PYSEC-2026-4244 ecosystem: pip exploitAvailable: true ssvc: exploitation: poc automatable: 'yes' technicalImpact: partial timestamp: '2026-10-05T16:25:31.396300Z' ingestedAt: '2026-10-02T22:33:09.846Z' --- ## Overview Multidict is an implementation of a multidict data structure. From 6.7.0 until 6.9.1, the C extension's items-view reflected union operation, operand | d.items(), in multidict_itemsview_or2_impl and subtraction operation, d.items() - operand, in multidict_itemsview_sub1_impl fail to release new key-identity and value references returned for each operand element. Applications that perform these operations over attacker-influenced sequences can leak two strong references per element, and garbage collection cannot reclaim them, so repeated operations can cause unbounded process memory growth and denial of service. Forward union, intersection, non-tuple operand elements, and pure-Python builds are not affected by this reference leak. This issue is fixed in version 6.9.1. ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Package advisory (CVE-2026-104874) Affected packages: - `multidict >= 6.7.0, <= 6.9.0` Patched in: - `multidict 6.9.1` Source: https://github.com/advisories/GHSA-54p9-h82j-f925 ## Vendor advisories - **Red Hat VEX** · Moderate · affected: Exploit Intelligence, Lightspeed Core, Migration Toolkit for Applications 8, OpenShift Lightspeed, Red Hat AI Inference Server, Red Hat Ansible Automation Platform 2, … · no fix planned: Exploit Intelligence, Red Hat Ansible Automation Platform 2, Red Hat Ansible Automation Platform Ansible Core 2, Red Hat Update Infrastructure 4 for Cloud Providers, … · updated 2026-10-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-104874.json) - **RHSA-2026:82415** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82415) - **RHSA-2026:82368** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82368) - **RHSA-2026:82061** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82061) - **RHSA-2026:82059** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82059) - **RHSA-2026:82371** · Red Hat · fixed in: Red Hat AI Inference Server 3.5 · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:82371) - **RHSA-2026:83116** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:83116) - **RHSA-2026:83112** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:83112) - **RHSA-2026:83120** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:83120) - **RHSA-2026:83121** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:83121) - **RHSA-2026:83114** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:83114)