{"id":"CVE-2026-42328","aliases":["GHSA-w239-58x2-q8p5","GO-2026-5684"],"title":"go-ipld-prime's DAG-CBOR and DAG-JSON decoders have unbounded recursion depth","summary":"go-ipld-prime's DAG-CBOR and DAG-JSON decoders have unbounded recursion depth","severity":"medium","cvss":6.2,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"ipld","product":"github.com/ipld/go-ipld-prime","ecosystem":"go","affected":["github.com/ipld/go-ipld-prime < 0.23.0"],"patched":["github.com/ipld/go-ipld-prime 0.23.0"],"published":"2026-05-07","updated":"2026-07-24","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-w239-58x2-q8p5","references":[{"url":"https://github.com/ipld/go-ipld-prime/security/advisories/GHSA-w239-58x2-q8p5"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42328"},{"url":"https://github.com/ipld/go-ipld-prime"}],"tags":["osv","go"],"epss":0.0012,"epssPercentile":0.02097,"ingestedAt":"2026-07-25T19:08:12.029Z","slug":"CVE-2026-42328","body":"## Overview\n\nThe DAG-CBOR and DAG-JSON decoders recurse on each nested map or list without a depth limit. A payload containing deeply nested collections causes the decoder to recurse once per level, growing the goroutine stack until the Go runtime terminates the process with a fatal stack overflow (distinct from a recoverable panic).\n\nFor DAG-CBOR, a payload of approximately 2 MB, consisting of repeated `0x81` (array-of-1) bytes followed by a terminator, produces around 2 million recursion frames and reliably exhausts Go's default 1 GB goroutine stack. The existing allocation budget does not prevent this: each nested collection header costs only a handful of budget units, so the stack is exhausted before the budget is. DAG-JSON has equivalent exposure via `[[[...]]]`-style payloads; it has no budget system and is therefore unprotected against recursion depth as well.\n\nSchema-free decoding (using `basicnode.Prototype.Any`) allows arbitrary nesting depth. Schema-bound decoding bounds nesting only when the schema itself is non-recursive and contains no fields typed as `Any`; schemas with recursive type references or any `Any`-typed fields permit unconstrained nesting at those points.\n\nThe fix adds a configurable `MaxDepth` option to both decoders, defaulting to 1024 nested levels. The decoder returns `ErrDecodeDepthExceeded` when a payload nests beyond the limit. Well-formed IPLD data rarely approaches this depth in practice; the default is generous for legitimate use while preventing stack exhaustion.\n\n## Affected packages\n\n- `github.com/ipld/go-ipld-prime < 0.23.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `github.com/ipld/go-ipld-prime 0.23.0`","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":34.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}