CVE-2026-72923
Description
In Microsoft.OpenApi.YamlReader from 2.0.0-preview.11 until 2.12.0 and from 3.0.0 until 3.10.0, and in Microsoft.OpenApi.Readers prior to 1.6.30, a small YAML OpenAPI document containing nested anchors and aliases can cause uncontrolled resource consumption when parsed through the public YAML reader APIs. YAML is parsed through SharpYaml, which represents aliases as shared nodes in a directed acyclic graph, so the parsed YAML graph stays small, but converting that graph to System.Text.Json.Nodes.JsonNode requires every alias to be materialized as an independent node because a JsonNode cannot be attached to multiple parents. Without a bound on that conversion work, a document with N nested anchors each referenced k times can require k^N materialized JSON nodes, leading to excessive memory allocation and process termination through out-of-memory conditions, a billion laughs style denial of service. The patched versions bound the YAML-to-JSON conversion by node count and nesting depth and report an OpenApiDiagnostic error instead of expanding without limit. This vulnerability is fixed in Microsoft.OpenApi.YamlReader 2.12.0 and 3.10.0, and Microsoft.OpenApi.Readers 1.6.30.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
CWEs
CWE-400
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.