Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). EPSS, Forum of Incident Response and Security Teams (FIRST), epss.first.org. Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-14257 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Juliangruber Brace-Expansion. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique SMS Pumping (T1496.003); ranked in the top 49% 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 SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-48285
Vulnerability Data
brace-expansion through 5.0.7 is vulnerable to denial of service via memory exhaustion. The expand() function limits the number of results with a max option (default 100,000) but does not bound the length of each result string. By chaining multiple brace…
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groups, an attacker keeps the result count under the limit while making each result progressively longer, so total memory scales with both count and string length until the process hits a fatal, uncatchable out-of-memory error. About 7.5 KB of input ('{a,b}'.repeat(1500)) crashes a default Node.js process. Any application that passes attacker-influenced strings to brace-expansion.expand() - directly or transitively via minimatch / glob brace patterns - can be crashed by a small request. Fixed in 5.0.8 by adding a maxLength option (default 4,000,000) that bounds accumulated output and intermediate arrays.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
MITRE ATT&CK v20.0
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 5 hardening rules · 3 OS baselines
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Mitigating Controls (NIST 800-53 r5)
Our mappings, made for this CVE.
Directly enforces a hard limit on concurrent sessions, structurally preventing unbounded resource allocation.
SC-5 directly limits the effects of resource-exhaustion events that constitute uncontrolled consumption.
SC-6 enforces explicit allocation limits on resources, structurally preventing the weakness from occurring.
Imposes a limit on consecutive invalid attempts, preventing one specific class of unbounded resource consumption.
Process isolation confines resource consumption to separate domains, reducing blast radius without stopping the root flaw.
Mitigating Controls (NIST CSF 2.0)
Our mappings, derived directly from the weakness types (CWEs) cited in the NVD entry via our CWE→CSF cross-walk — links open the control.
Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.
Mitigating Controls (ISO/IEC 27001:2022 Annex A)
Our mappings, derived directly from the weakness types (CWEs) cited in the NVD entry via our CWE→ISO cross-walk — links open the control.
Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.
A.8.29's combined programme of code review, static analysis, dynamic testing and penetration testing reaches CWE-770 through both SOURCE and RUNTIME: missing throttling, unbounded allocation loops and absent connection limits are patterns static analysis and code review surface, and DoS-style stress testing catches them at runtime. The remainder is bounded and nameable — limits that exist but are set too high for the deployment context, race conditions in resource accounting, and design-level decisions about whether a limit belongs at all — which keeps this below the `full` rung A.8.29 reaches on CWE-89.
Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.
Monitoring network service usage and applying controls to restrict access when necessary limits an attacker’s ability to consume excessive resources through unrestricted or unauthenticated service calls.
A.8.28 mandates secure coding practices — threat modelling, coding standards, peer review, knowledge of common defects — that can catch missing resource limits before code ships, but it is a fallible human practice whose coverage depends on implementer rigour, leaving a nameable remainder that A.8.29 testing reaches more reliably.
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 our cross-walk; rows rated `none` are excluded, and each rule says how its mapping was checked.
Definition changed on 29 October 2026. Until then this section listed every rule rated above none, partial included. From that date it lists rules whose mapping is rated full or mostly and checked at llm_unverified or higher; partial mappings show when you ask.
Oracle Linux 8 (1 rule, 1 more partial)
- V-248552 OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. blocks 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. blocks CWE-770
Oracle Linux 9 (1 rule, 1 more partial)
- V-271710 OL 9 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. blocks CWE-770
- V-271709 OL 9 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. blocks 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. blocks CWE-770