node-opcua: Unbounded nonce cache enables unauthenticated heap exhaustion DoS

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.

node-opcua is an OPC UA implementation for TypeScript and Node.js. Prior to 2.166.0, the process-global g_alreadyUsedNonce cache used by nonceAlreadyBeenUsed in packages/node-opcua-secure-channel/source/server/server_secure_channel_layer.ts records nonces from OpenSecureChannelRequest and CreateSession without expiration or a size limit. An unauthenticated remote attacker can repeatedly create sessions with unique nonces, causing entries to persist after session expiry and accumulate across connection cycles even when maxSessions=10 limits concurrent sessions. The resulting unbounded heap growth can exhaust the default Node.js heap and crash the node-opcua server process. This issue is fixed in version 2.166.0.

Source published

14 Sep 2026 16:09:07 UTC

Source modified

14 Sep 2026 16:35:48 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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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: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

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

node-opcua is an OPC UA implementation for TypeScript and Node.js. Prior to 2.166.0, the process-global g_alreadyUsedNonce cache used by nonceAlreadyBeenUsed in packages/node-opcua-secure-channel/source/server/server_secure_channel_layer.ts records nonces from OpenSecureChannelRequest and CreateSession without expiration or a size limit. An unauthenticated remote attacker can repeatedly create sessions with unique nonces, causing entries to persist after session expiry and accumulate across connection cycles even when maxSessions=10 limits concurrent sessions. The resulting unbounded heap growth can exhaust the default Node.js heap and crash the node-opcua server process. This issue is fixed in version 2.166.0.

Source published

Sep 14, 2026, 4:09:07 PM (timezone not stated)

Source modified

Sep 14, 2026, 4:35:48 PM (timezone not stated)

Observed here

11 Nov 2026 13:59:00 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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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: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

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

node-opcua is an OPC UA implementation for TypeScript and Node.js. Prior to 2.166.0, the process-global g_alreadyUsedNonce cache used by nonceAlreadyBeenUsed in packages/node-opcua-secure-channel/source/server/server_secure_channel_layer.ts records nonces from OpenSecureChannelRequest and CreateSession without expiration or a size limit. An unauthenticated remote attacker can repeatedly create sessions with unique nonces, causing entries to persist after session expiry and accumulate across connection cycles even when maxSessions=10 limits concurrent sessions. The resulting unbounded heap growth can exhaust the default Node.js heap and crash the node-opcua server process. This issue is fixed in version 2.166.0.

Source published

14 Sep 2026 17:17:46 UTC

Source modified

30 Sep 2026 19:38:27 UTC

Observed here

25 Oct 2026 13:17:22 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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: 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** A process-global nonce cache with no eviction policy allows an unauthenticated remote attacker to exhaust server heap memory by repeatedly opening sessions, causing the node-opcua server process to crash. **Affected versions:** <= 2.165.0 **Tested version:** 2.165.0 **CVSS Score:** 7.5 (High) **CVSS Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H **CWE:** CWE-770 Allocation of Resources Without Limits or Throttling --- **Root Cause** In `packages/node-opcua-secure-channel/source/server/server_secure_channel_layer.ts` at line 156, `g_alreadyUsedNonce` is a process-global object used to track previously seen nonces for replay detection. Entries are added on every `OpenSecureChannelRequest` and every `CreateSession` request but are never removed or expired. An unauthenticated attacker can exploit the `CreateSession` path (which requires no certificate) to accumulate nonce entries indefinitely. Even with `maxSessions=10` limiting concurrent sessions, nonces persist after session expiry, allowing slow but reliable heap exhaustion across repeated connection cycles. --- **Measured Impact** Dynamically confirmed heap growth: - 5,000 unique nonces → +1.23 MB resident heap, no eviction after explicit GC - Projected: 10^6 nonces → ~246 MB resident heap - Achievable OOM on default Node.js heap limits --- **Suggested Fix** Add a TTL-based eviction policy to `g_alreadyUsedNonce`. Nonces should be expired after the maximum session timeout (or a reasonable fixed window, e.g. 1 hour). A Map with timestamp entries and periodic cleanup is sufficient. --- I am following a 90-day responsible disclosure policy. I am happy to provide additional technical details under embargo. Please confirm receipt at your earliest convenience. Reporter: Stanley Tobias Discovery date: 2026-03-23

Source published

20 Aug 2026 18:35:41 UTC

Source modified

27 Aug 2026 19:15:07 UTC

Observed here

24 Oct 2026 13:17:17 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