Cyber Resilience

CVE-2026-21710

Memory Safety

Memory SafetyDoS
Published
30 March 2026
Modified
15 July 2026
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.26 98th percentile
Risk Priority 72 floored blend · peak EPSS

Summary

CVE-2026-21710 is a high-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Nodejs (inferred from references). Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Denial of Service (T1498); ranked in the top 2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-10 (Concurrent Session Control) and SA-11 (Developer Testing and Evaluation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A flaw in Node.js HTTP request handling causes an uncaught `TypeError` when a request is received with a header named `__proto__` and the application accesses `req.headersDistinct`. When this occurs, `dest["__proto__"]` resolves to `Object.prototype` rather than `undefined`, causing `.push()` to be…

more

called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by `error` event listeners, meaning it cannot be handled without wrapping every `req.headersDistinct` access in a `try/catch`. * This vulnerability affects all Node.js HTTP servers on **20.x, 22.x, 24.x, and v25.x**

CWE(s)
CWE-770CWE-843

Related Threats

MITRE ATT&CK Enterprise Techniques

T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
attack.mitre.org →
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1498.001 Direct Network Flood Impact
Adversaries may attempt to cause a denial of service (DoS) by directly sending a high-volume of network traffic to a target.
attack.mitre.org →
T1498.002 Reflection Amplification Impact
Adversaries may attempt to cause a denial of service (DoS) by reflecting a high-volume of network traffic to a target.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-12385Shared CWE-770
CVE-2026-20608Shared CWE-770
CVE-2026-44004Shared CWE-770
CVE-2026-29062Shared CWE-770
CVE-2026-34165Shared CWE-770
CVE-2023-0568Shared CWE-770
CVE-2026-34824Shared CWE-770
CVE-2023-1544Shared CWE-770
CVE-2023-26285Shared CWE-770
CVE-2026-44216Shared CWE-770

Affected Assets

Nodejs
—
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.4
  • V1.5.2
  • V3.2.3
  • V15.3.5

Mitigating Controls (NIST 800-53 r5) AI

AC-10 Concurrent Session Control good match

Directly enforces a hard limit on concurrent sessions, structurally preventing unbounded resource allocation.

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (including fuzzing and type-aware analysis) directly finds type-confusion flaws before deployment.

SC-6 Resource Availability good match

Requires explicit allocation of resources by priority or quota, directly stopping unlimited allocation.

AC-7 Unsuccessful Logon Attempts partial match

Imposes a limit on consecutive invalid attempts, preventing one specific class of unbounded resource consumption.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can require use of type-safe languages, static typing, and runtime type checks that structurally avoid allocating one type and accessing another.

SC-5 Denial-of-service Protection partial match

Reduces impact of resulting DoS events without preventing the underlying lack of allocation limits.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
degrades

Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent type-confusion flaws via safe typing, static analysis, and code review while the control itself addresses many additional weaknesses.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.16 Monitoring activities mostly match
finds

Baseline comparison of CPU, memory and bandwidth usage helps surface uncontrolled resource allocations before they cause service degradation.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect type-confusion vulnerabilities through fuzzing and static analysis.

A.8.6 Capacity management mostly match
prevents

Capacity projections and elasticity measures ensure that allocation requests are bounded and can be throttled, reducing the window in which an attacker can force unbounded resource reservations.

A.8.13 Information backup partial match
mitigates

Defining retention periods and deletion schedules for backup copies prevents indefinite accumulation of data on storage media without corresponding resource-management controls.

A.8.14 Redundancy of information processing facilities partial match
mitigates

Architectural redundancy and automatic failover limit the impact of an attacker who forces excessive allocations, because spare capacity can absorb the load until the primary instance recovers.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates type-safe design and review that can catch type-confusion flaws.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248552 OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770
  • V-248553 OL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-770
Oracle Linux 9 (2 rules)
  • V-271710 OL 9 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-770
  • V-271709 OL 9 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770
RHEL 8 (1 rule)
  • V-230244 RHEL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770

References