Seroval `fromJSON`/`fromCrossJSON` denial of service via unvalidated array node length

### Summary `fromJSON` and `fromCrossJSON` did not check that an array node's element list is an array. A small crafted payload could set the length the decoder used. That length controlled how much memory was allocated and how many times the decoder looped, and it did not depend on the size of the payload. ### Impact A service that passes untrusted input to `fromJSON` or `fromCrossJSON` can be made unavailable by an unauthenticated request. - A small payload can allocate enough memory to end the process. - A small payload can block the thread for seconds, or without end. This affects any framework that decodes request bodies with these functions before its own validation runs. This issue is a bypass of the fix for GHSA-66fc-rw6m-c2q6 in 1.4.1. ### Patches Fixed in `[email protected]`. The deserializer now rejects any node whose element list is not an array, and throws `SerovalMalformedNodeError`. ### Workarounds None. Upgrade to 1.6.8.

Source published

28 Oct 2026 21:17:20 UTC

Source modified

28 Oct 2026 21:30:05 UTC

Observed here

28 Oct 2026 21:55:29 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Publisher rating · HIGH