Cyber Resilience

CVE-2026-49234

HighUpdated

Published: 08 June 2026

Published
08 June 2026
Modified
17 June 2026
KEV Added
Patch
CVSS Score v4 8.2 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0026 17.3th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-49234 is a high-severity Improper Input Validation (CWE-20) vulnerability in Nlnetlabs Routinator. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 17.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

When sending a specifically crafted non-UTF-8 string as select-asn query parameter to the /api/v1/origins endpoint, Routinator crashes. This only affects users who allow API access from untrusted networks.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

CWE-20 input validation flaw on exposed API endpoint directly enables remote crash/DoS via crafted request (T1499.004) when the service is reachable from untrusted networks (T1190).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

nlnetlabs
routinator
≤ 0.15.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-20

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References