Security Resilience

CVE-2024-1899

DoS in Showdownjs Showdown ≤ 2.1.0

Public PoCDoS
Published
26 February 2024
Modified
17 June 2026
CVSS Score v3.1 5.3
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:L
EPSS Score 0.0081 56th percentile
Risk Priority 46 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2024-1899 is a medium-severity Uncontrolled Recursion (CWE-674) vulnerability in Showdownjs Showdown. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 44% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

An issue in the anchors subparser of Showdownjs versions <= 2.1.0 could allow a remote attacker to cause denial of service conditions.

CWE(s)

Related Threats

CVEs Like This One

CVE-2026-47306Shared CWE-674
CVE-2024-31228Shared CWE-674
CVE-2026-14803Shared CWE-674
CVE-2025-67899Shared CWE-674
CVE-2026-69378Shared CWE-674
CVE-2026-63737Shared CWE-674
CVE-2026-89418Shared CWE-674
CVE-2025-50420Shared CWE-674
CVE-2024-58102Shared CWE-674
CVE-2026-64194Shared CWE-674

Affected Assets

showdownjs
showdown
≤ 2.1.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Input validation can reject or constrain data that would otherwise drive unbounded recursive calls.

DoS protection mechanisms limit the resource-exhaustion impact of uncontrolled recursion without eliminating the flaw.

System monitoring can observe anomalous resource consumption that signals runaway recursion after it begins.

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.

blocks

Secure development life cycle requires controls that prevent uncontrolled recursion through design and code review.

blocks

A.8.26 only requires that security requirements (including resilience against attacks such as buffer overflows) be identified and specified during development or acquisition; it does not itself enforce, implement, or prevent uncontrolled recursion from being exploitable in the resulting application.

blocks

A.8.27 mandates establishing and applying secure engineering principles (defense-in-depth, least privilege, security by design, input distrust, hardening, design reviews) but does not itself stop uncontrolled recursion from being introduced or from consuming excessive resources when present; the weakness can still be exploited.

prevents

Secure coding standards directly prohibit or constrain recursive constructs that could exhaust stack or memory.

finds

Security testing in development can detect excessive recursion via static analysis or fuzzing.

finds

Capacity management includes monitoring and limits that mitigate resource exhaustion from runaway recursion.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-674, a class-level weakness, and none of its children carries one either.

References