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

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. From 1.4.1 until 1.6.8, fromJSON and fromCrossJSON do not require an array node's element list to be an actual array. A small crafted payload can supply an attacker-controlled length that determines memory allocation and decoder iterations independently of payload size, allowing an unauthenticated request to exhaust the process or block its thread. This issue is a residual bypass of the remediation for CVE-2026-23957. This issue is fixed in version 1.6.8.

Source published

26 Oct 2026 20:52:38 UTC

Source modified

26 Oct 2026 20:52:38 UTC

Observed here

26 Oct 2026 21:35:30 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. From 1.4.1 until 1.6.8, fromJSON and fromCrossJSON do not require an array node's element list to be an actual array. A small crafted payload can supply an attacker-controlled length that determines memory allocation and decoder iterations independently of payload size, allowing an unauthenticated request to exhaust the process or block its thread. This issue is a residual bypass of the remediation for CVE-2026-23957. This issue is fixed in version 1.6.8.

Source published

Oct 26, 2026, 8:52:38 PM (timezone not stated)

Source modified

Oct 26, 2026, 8:52:38 PM (timezone not stated)

Observed here

28 Oct 2026 21:57:40 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Seroval facilitates JavaScript value stringification, including complex structures beyond JSON.stringify capabilities. From 1.4.1 until 1.6.8, fromJSON and fromCrossJSON do not require an array node's element list to be an actual array. A small crafted payload can supply an attacker-controlled length that determines memory allocation and decoder iterations independently of payload size, allowing an unauthenticated request to exhaust the process or block its thread. This issue is a residual bypass of the remediation for CVE-2026-23957. This issue is fixed in version 1.6.8.

Source published

26 Oct 2026 21:18:17 UTC

Source modified

26 Oct 2026 21:18:17 UTC

Observed here

28 Oct 2026 21:57:06 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

### 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

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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