CVE Catalog

CVE-2026-57023

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.46%

37th percentile - higher than 37% of all known CVEs

Summary

An improper validation of specified quantity in input vulnerability in the TCP proxy plugin of Juniper Networks Junos OS on MX Series with SPC3 and SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial of Service (DoS) by sending a TCP packet with a malformed header, crashing the flowd process.

Risk Assessment

This attack can cause a complete service outage until the system automatically recovers, posing a significant risk to infrastructure availability.

Recommendation

Immediately upgrade Junos OS to a fixed version: 23.4R2-S7, 24.2R2-S4, 24.4R2-S3, or 25.2R2 depending on the branch in use.

Other vulnerabilities in Junos OS

See all
Original NVD description (English source)

An Improper Validation of Specified Quantity in Input vulnerability in the TCP proxy plugin of Juniper Networks Junos OS on MX Series with SPC3, and SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial of Service (DoS). When TCP proxy is engaged in a flow session, to support ALGs, Advanced Anti-Malware, ICAP or UTM, a TCP packet with specifically malformed TCP header will cause flow processing daemon (flowd) to crash and restart. This causes a complete service outage until the system has automatically recovered. This issue affects Junos OS on MX with SPC3, and SRX Series:  * 23.4 versions before 23.4R2-S7,  * 24.2 versions before 24.2R2-S4,  * 24.4 versions before 24.4R2-S3, * 25.2 versions before 25.2R2. This issue does not affect releases before 23.4R1.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS