Junos OS: MX with SPC3, SRX Series: A specifically malformed TCP packet causes a flowd crash
Summary
| CVE | CVE-2026-57023 |
|---|---|
| State | PUBLISHED |
| Assigner | juniper |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-09 22:17:07 UTC |
| Updated | 2026-07-14 15:19:42 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 8.7 HIGH from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/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:Y/R:A/V:X/RE:M/U:X
EPSS: 0.004610000 probability, percentile 0.369350000 (date 2026-07-14)
Problem Types: CWE-1284 | CWE-1284 CWE-1284 Improper Validation of Specified Quantity in Input
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 8.7 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/C... |
| 4.0 | CNA | CVSS | 8.7 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/... |
| 3.1 | [email protected] | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
NoneAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
LowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/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:Y/R:A/V:X/RE:M/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Juniper | Junos | 23.4 | - | All | All |
| Operating System | Juniper | Junos | 23.4 | r1 | All | All |
| Operating System | Juniper | Junos | 23.4 | r1-s1 | All | All |
| Operating System | Juniper | Junos | 23.4 | r1-s2 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s1 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s2 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s3 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s4 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s5 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s6 | All | All |
| Operating System | Juniper | Junos | 24.2 | - | All | All |
| Operating System | Juniper | Junos | 24.2 | r1 | All | All |
| Operating System | Juniper | Junos | 24.2 | r1-s1 | All | All |
| Operating System | Juniper | Junos | 24.2 | r1-s2 | All | All |
| Operating System | Juniper | Junos | 24.2 | r2 | All | All |
| Operating System | Juniper | Junos | 24.2 | r2-s1 | All | All |
| Operating System | Juniper | Junos | 24.2 | r2-s2 | All | All |
| Operating System | Juniper | Junos | 24.2 | r2-s3 | All | All |
| Operating System | Juniper | Junos | 24.4 | - | All | All |
| Operating System | Juniper | Junos | 24.4 | r1 | All | All |
| Operating System | Juniper | Junos | 24.4 | r1-s2 | All | All |
| Operating System | Juniper | Junos | 24.4 | r1-s3 | All | All |
| Operating System | Juniper | Junos | 24.4 | r2 | All | All |
| Operating System | Juniper | Junos | 24.4 | r2-s1 | All | All |
| Operating System | Juniper | Junos | 24.4 | r2-s2 | All | All |
| Operating System | Juniper | Junos | 25.2 | - | All | All |
| Operating System | Juniper | Junos | 25.2 | r1 | All | All |
| Operating System | Juniper | Junos | 25.2 | r1-s1 | All | All |
| Operating System | Juniper | Junos | 25.2 | r1-s2 | All | All |
| Hardware | Juniper | Mx-spc3 | - | All | All | All |
| Hardware | Juniper | Mx240 | - | All | All | All |
| Hardware | Juniper | Mx480 | - | All | All | All |
| Hardware | Juniper | Mx960 | - | All | All | All |
| Hardware | Juniper | Srx1500 | - | All | All | All |
| Hardware | Juniper | Srx1600 | - | All | All | All |
| Hardware | Juniper | Srx2300 | - | All | All | All |
| Hardware | Juniper | Srx300 | - | All | All | All |
| Hardware | Juniper | Srx320 | - | All | All | All |
| Hardware | Juniper | Srx340 | - | All | All | All |
| Hardware | Juniper | Srx345 | - | All | All | All |
| Hardware | Juniper | Srx380 | - | All | All | All |
| Hardware | Juniper | Srx400 | - | All | All | All |
| Hardware | Juniper | Srx4100 | - | All | All | All |
| Hardware | Juniper | Srx4120 | - | All | All | All |
| Hardware | Juniper | Srx4200 | - | All | All | All |
| Hardware | Juniper | Srx4300 | - | All | All | All |
| Hardware | Juniper | Srx440 | - | All | All | All |
| Hardware | Juniper | Srx4600 | - | All | All | All |
| Hardware | Juniper | Srx4700 | - | All | All | All |
| Hardware | Juniper | Srx5400 | - | All | All | All |
| Hardware | Juniper | Srx5600 | - | All | All | All |
| Hardware | Juniper | Srx5800 | - | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Juniper Networks | Junos OS | affected 23.4 23.4R2-S7 custom | SRX Series, MX Series with SPC3 |
| CNA | Juniper Networks | Junos OS | affected 24.2 24.2R2-S4 custom | SRX Series, MX Series with SPC3 |
| CNA | Juniper Networks | Junos OS | affected 24.4 24.4R2-S3 custom | SRX Series, MX Series with SPC3 |
| CNA | Juniper Networks | Junos OS | affected 25.2 25.2R2 custom | SRX Series, MX Series with SPC3 |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| supportportal.juniper.net/JSA110083 | [email protected] | supportportal.juniper.net | Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
Solutions
CNA: The following software releases have been updated to resolve this specific issue: 23.4R2-S7, 24.2R2-S4, 24.4R2-S3, 25.2R2, 25.4R1, and all subsequent releases.
Workarounds
CNA: There are no known workarounds for this issue.
Exploits
CNA: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
There are currently no legacy QID mappings associated with this CVE.