CVE-2026-57023: 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 unauthenti
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.
Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-57023
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-570230.46% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 37% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-57023 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- high[NEW] [high] Juniper JUNOS and JUNOS Evolved: Multiple vulnerabilitiescert-bund
- unknownJuniper Junos OS Multiple Vulnerabilitieshkcert
- unknownMultiple vulnerabilities in Juniper Networks products (July 09, 2026)cert-fr-avis
Recent advisories for An Improper Validation
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- unknownCVE-2026-49844: Improper encoding of non-finite floating-point values during MapMessage JSON serialization in …nvd · 2026-07-10
- mediumCVE-2026-56312: Capgo before 12.128.2 contains an improper validation vulnerability in the accept_invitation e…nvd · 2026-07-10
- highCVE-2026-40454: Out-of-bounds Read, Improper Input Validation vulnerability in Apache IoTDB C++ client. Out-of…nvd · 2026-07-10
- unknownCVE-2026-21057: Improper input validation in Samsung Pass prior to version 5.2.10.3 allows local privileged at…nvd · 2026-07-10
- unknownCVE-2026-21053: Improper input validation in Samsung Email prior to version 6.2.13.1 allows local attackers to…nvd · 2026-07-10
- highCVE-2026-15288: The SureForms – Drag and Drop Form Builder for WordPress plugin for WordPress is vulnerable to…nvd · 2026-07-10
More from NVD Recent CVEs
- unknownCVE-2026-57828: The Joomla extension Phoca Downloads is vulnerable to an authenticated arbitrary file upload t…2026-07-11
- unknownCVE-2026-57827: The Joomla extension RSFiles is vulnerable to an unauthenticated arbitrary file upload that al…2026-07-11
- highCVE-2026-1359: The Genolve – AI image AI video generation plugin for WordPress is vulnerable to unauthorized m…2026-07-11
- highCVE-2026-9282: The W3 Total Cache plugin for WordPress is vulnerable to Directory Traversal in all versions up…2026-07-11
- mediumCVE-2026-9017: The NEX-Forms – Ultimate Forms Plugin for WordPress plugin for WordPress is vulnerable to autho…2026-07-11