Junos OS (SRX firewalls)
CVE-2024-39526: MX Series with MPC10/MPC11/LC9600, MX304, EX9200, PTX Series: Receipt of malformed DHCP packets causes interfaces to stop processing packets
An Improper Handling of Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS on MX Series with MPC10/MPC11/LC9600 line cards, EX9200 with EX9200-15C lines cards, MX304 devices, and Juniper Networks Junos OS Evolved on PTX Series, allows an attacker sending malformed DHCP packets to cause ingress packet processing to stop, leading to a Denial of Service (DoS).
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS (MX Series, MX304, EX9200) 0 | 21.2R3-S7 or later |
| Junos OS (MX Series, MX304, EX9200) 21.4 | 21.4R3-S6 or later |
| Junos OS (MX Series, MX304, EX9200) 22.2 | 22.2R3-S3 or later |
| Junos OS (MX Series, MX304, EX9200) 22.3 | See the advisory |
| Junos OS (MX Series, MX304, EX9200) 22.4 | 22.4R3 or later |
| Junos OS (MX Series, MX304, EX9200) 23.2 | 23.2R2 or later |
| Junos OS Evolved (PTX Series) 19.3R1-EVO | 21.2R3-S8-EVO or later |
| Junos OS Evolved (PTX Series) 21.4-EVO | 21.4R3-S7-EVO or later |
| Junos OS Evolved (PTX Series) 22.1-EVO | 22.1R3-S6-EVO or later |
| Junos OS Evolved (PTX Series) 22.2-EVO | 22.2R3-S5-EVO or later |
| Junos OS Evolved (PTX Series) 22.3-EVO | 22.3R3-S3-EVO or later |
| Junos OS Evolved (PTX Series) 22.4-EVO | 22.4R3-S1-EVO or later |
| Junos OS Evolved (PTX Series) 23.2-EVO | 23.2R2-S2-EVO or later |
| Junos OS Evolved (PTX Series) 23.4-EVO | 23.4R2-EVO or later |
| Junos OS Evolved (PTX Series) 0 | Not affected |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Improper Handling of Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS on MX Series with MPC10/MPC11/LC9600 line cards, EX9200 with EX9200-15C lines cards, MX304 devices, and Juniper Networks Junos OS Evolved on PTX Series, allows an attacker sending malformed DHCP packets to cause ingress packet processing to stop, leading to a Denial of Service (DoS). Continued receipt and processing of these packets will create a sustained Denial of Service (DoS) condition.
This issue only occurs if DHCP snooping is enabled. See configuration below.
This issue can be detected using following commands. Their output will display the interface status going down:
user@device>show interfaces <if--x/x/x> user@device>show log messages | match <if--x/x/x> user@device>show log messages ==> will display the "[Error] Wedge-Detect : Host Loopback Wedge Detected: PFE: no," logs.
This issue affects: Junos OS on
MX Series
with MPC10/MPC11/LC9600 line cards, EX9200 with EX9200-15C line cards, and MX304:
- All versions before 21.2R3-S7,
- from 21.4 before 21.4R3-S6,
- from 22.2 before 22.2R3-S3,
- all versions of 22.3,
- from 22.4 before 22.4R3,
- from 23.2 before 23.2R2;
Junos OS Evolved on PTX Series: * from 19.3R1-EVO before 21.2R3-S8-EVO,
- from 21.4-EVO before 21.4R3-S7-EVO,
- from 22.1-EVO before 22.1R3-S6-EVO,
- from 22.2-EVO before 22.2R3-S5-EVO,
- from 22.3-EVO before 22.3R3-S3-EVO,
- from 22.4-EVO before 22.4R3-S1-EVO,
- from 23.2-EVO before 23.2R2-S2-EVO,
- from 23.4-EVO before 23.4R2-EVO.
Junos OS Evolved releases prior to 19.3R1-EVO are unaffected by this vulnerability
Am I affected?
DHCP snooping is enabled when the following options are configured:
[forwarding-options dhcp-relay] [system services dhcp-local-server]
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.