Security Vulnerabilities
An Improper Handling of Undefined Parameters vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on EX Series devices allows an authenticated attacker with low privileges to cause a Denial-of-Service (DoS).
If an attempt is made to subscribe to an unsupported telemetry sensor path on EX2300, EX3400, EX4000, EX4100 and EX4400 via gRPC, this causes the FPC to crash. This leads to a complete service outage until the module has automatically restarted.
The following log message can be seen when this issue happens:
agentd[<PID>]: AGENTD_RESOURCE_NOT_FOUND: No resource name found for <sensor>
This issue affects Junos OS on
EX2300, EX3400, EX4000, EX4100 and EX4400
devices:
* all versions before 23.2R2-S7,
* 23.4 versions before 23.4R2-S8,
* 24.2 versions before 24.2R2-S5,
* 24.4 versions before 24.4R2.
CVSS Score
7.1
EPSS Score
0.004
Published
2026-07-09
A Use of Incorrectly-Resolved Name or Reference vulnerability in the URL filtering plugin of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass web filtering and access downstream resources that should be unreachable.
If an MX Series device is configured with web filtering, and an attacker sends a request with a specifically formatted URL, this request will get forwarded despite the system being configured to block it. In turn, an attacker can access downstream resources that are expected to be unreachable.
This issue affects Junos OS on MX Series:
* all versions before 23.2R2-S7,
* 23.4 versions before 23.4R2-S8,
* 24.2 versions before 24.2R2-S5,
* 24.4 versions before 24.4R2-S4,
* 25.2 versions before 25.2R2-S1,
* 25.4 versions before 25.4R1-S2, 25.4R2.
CVSS Score
6.9
EPSS Score
0.003
Published
2026-07-09
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CVSS Score
5.3
EPSS Score
0.003
Published
2026-07-09
A Missing Release of Memory after Effective Lifetime vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX Series devices allows an unauthenticated adjacent attacker to cause a Denial-of-Service (DoS).When sFlow is configured in a Virtual Chassis (VC) scenario with EX4100 Series or EX4400 Series devices, multicast traffic which is received on one VC member and sent out on another member leads to a memory leak and ultimately an FPC crash and restart.
The leak can be monitored by watching the continuous increase of the buffer values in the output of:
user@host> show chassis fpc
This issue affects Junos OS on EX4100 Series and EX4400:
* all versions before 23.2R2-S7,
* 23.4 versions before 23.4R2-S7,
* 24.2 versions before 24.2R2-S4,
* 24.4 versions before 24.4R2.
CVSS Score
7.1
EPSS Score
0.003
Published
2026-07-09
An Improper Restriction of Communication Channel to Intended Endpoints vulnerability in Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause license exhaustion.
Due to an incorrect initialization, a process which should only be able to communicate internally within the device, can be reached over the network via an open port. This leads to unauthorized access to the license management.
This issue affects all Junos OS Evolved versions before 23.2R2-EVO.
CVSS Score
6.9
EPSS Score
0.003
Published
2026-07-09
A Missing Synchronization vulnerability in the flow collector handler of Juniper Networks Junos OS Evolved on QFX Series allows an adjacent, unauthenticated attacker to cause a Denial-of-Service (DoS).
When the reachability of an sFlow collector changes, the corresponding next-hop entry is updated. If this update occurs simultaneously with the sFlow thread accessing the next-hop data (which is outside the attackers control), it causes the evo-pfemand process to crash, impacting all traffic forwarding until the automatic process restart has completed.
This issue affects Junos OS Evolved on QFX Series:
* all 23.2 versions,
* 23.4 versions before 23.4R2-S7-EVO,
* 24.2 versions before 24.2R2-S5-EVO,
* 24.4 versions before 24.4R2-S3-EVO,
* 25.2 versions before 25.2R2-EVO.
CVSS Score
6.0
EPSS Score
0.002
Published
2026-07-09
A Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).
As part of the stateful traffic processing on SRX Series devices flows are being established, and removed when not needed anymore. During the removal process the timeout of a flow should be set to 3 seconds and consequentially the flow should be removed shortly after. Due to a race condition occurring when setting the timeout there is a chance (the exact conditions are outside the attackers control) that the timeout is instead set to a very high value of larger than 10,000 seconds:
user@host> show security flow session | match timeout
Session ID: 98784248524, Policy name: PROD-FLOW/4, HA State: Active, Timeout: 85250, Session State: Valid
This will lead to an accumulation of flows which can be observed by an ever-increasing value of invalidated sessions in the output of 'show security flow session summary':
user@host> show security flow session summary | match invalid
Invalidated sessions: 216931These sessions can't be cleared manually with the 'clear security flow session' command, which will either lead to forwarding to stop (and the system needs to be manually recovered with a reboot) or to a flowd core and automatic reboot.
This issue affects Junos OS on SRX Series:
* 24.2 versions before 24.2R2-S3,
* 24.4 versions before 24.4R2-S1, 24.4R2-S2,
* 25.2 versions before 25.2R1-S2, 25.2R2.
This issue does not affect releases earlier than 24.2R1;
CVSS Score
8.2
EPSS Score
0.004
Published
2026-07-09
An Out-of-bounds Write vulnerability in the http-gatekeeper (http-gk) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).
If an SRX Series device is configured for remote-access VPN with pre-logon compliance check, a network-based attacker sending specifically formatted requests can trigger an out of bounds write leading to an http-gk process crash. This crash leads to unavailability of all services depending on the [ system services web-management ] configuration (like J-Web, remote access VPN and firewall authentication) until the process automatically restarts.
This issue affects Junos OS on SRX Series:
* 23.2 versions before 23.2R2-S7,
* 23.4 versions before 23.4R2-S8,
* 24.2 versions before 24.2R2-S4,
* 24.4 versions before 24.4R2-S4,
* 25.2 versions before 25.2R2,
* 25.4 versions before 25.4R1-S1, 25.4R2.
CVSS Score
6.9
EPSS Score
0.005
Published
2026-07-09
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX with SPC3 and SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).
When an affected device initiates a TCP connection to an attacker-controlled system that responds with a specific packet, this causes a PFE crash and restart, which affects all services until the system has automatically recovered.
This issue can happen among others in the following scenarios: ALG, SSL proxy, UTM, RTLOG, AppQoE probing, AAMW, ICAP, URL filtering.
This issue affects Junos OS on MX Series with SPC3, SRX5k Series with SPC3, SRX1600 Series, SRX2300 Series, SRX4000 Series, and vSRX Series:
* all versions before 23.2R2-S4,
* 23.4 versions before 23.4R2-S5,
* 24.2 versions before 24.2R2.
CVSS Score
8.2
EPSS Score
0.004
Published
2026-07-09
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.
CVSS Score
8.7
EPSS Score
0.005
Published
2026-07-09