A reachable assertion vulnerability exists in the na‑grpcd process of Junos OS Evolved. It allows a remote unauthenticated attacker to crash the daemon by sending a gRPC telemetry subscription request, resulting in a denial of service. The weakness is classified as CWE‑617.

Juniper Networks Junos OS Evolved devices are affected. The vulnerability exists in the following releases: 23.2R2‑S7.7‑EVO, 23.4R2‑S8.11‑EVO, 24.2R2‑S5.6‑EVO, 24.4R2‑S5‑EVO, 25.2R2‑S2‑EVO, 25.2X100‑D35‑EVO, 25.4R1‑S3‑EVO, 25.4R2‑EVO, 25.4X300‑D40‑EVO, 26.2R1‑S2‑EVO, 26.2R2‑EVO, 26.4R1‑EVO, and all subsequent releases.

The CVSS score of 8.7 highlights a high severity denial‑of‑service risk. With an EPSS score of 0.00573 (<1%), the likelihood of exploitation remains low, yet the vulnerability is not listed in the CISA KEV catalog. Because an unauthenticated attacker can send a crafted gRPC telemetry request over the network, the attack vector is inferred to be remote, potentially from any host with network reach to the Junos device.