CVE-2026-11946

highCVSS 7.5covered by 1 sourcefirst seen 2026-07-02

An unauthenticated remote attacker can exhaust server memory via the GetEndpoints Discovery Service in open62541. The endpointUrl field of GetEndpointsRequest is not validated for length. An attacker can declare an arbitrarily large string (up to ~4.09 GB via the UInt32 length field) delivered across intermediate chunks without ever sending the final chunk. The server buffers all chunks in RAM indefinitely until the SecureChannel times out. The attack is pre-session and bypasses all encryption configurations. The issue affects open62541: from 1.4.0 through 1.4.16, from 1.5.0 through 1.5.4, master.

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Exploitation outlook

Low exploitation risk0.39% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 31% of all EPSS-scored CVEs.

Advisory coverage (1)

highCVE-2026-11946: An unauthenticated remote attacker can exhaust server memory via the GetEndpoints Discovery Se…nvd · 2026-07-02

External references

NVD record for CVE-2026-11946

CVE.org record

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