A Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in the SIP application layer gateway (ALG) of Juniper Networks Junos OS on SRX Series and MX Series with MX-SPC3 or MS-MPC allows an unauthenticated network-based attacker sending specific SIP messages over TCP to crash the flow management process, leading to a Denial of Service (DoS).
On SRX Series, and MX Series with MX-SPC3 or MS-MPC service cards, receipt of multiple SIP messages causes the SIP headers to be parsed incorrectly, eventually causing a continuous loop and leading to a watchdog timer expiration, crashing the flowd process on SRX Series and MX Series with MX-SPC3, or mspmand process on MX Series with MS-MPC.
This issue only occurs over TCP. SIP messages sent over UDP cannot trigger this issue.
This issue affects Junos OS on SRX Series and MX Series with MX-SPC3 and MS-MPC:
* all versions before 21.2R3-S10,
* from 21.4 before 21.4R3-S12,
* from 22.4 before 22.4R3-S8,
* from 23.2 before 23.2R2-S5,
* from 23.4 before 23.4R2-S6,
* from 24.2 before 24.2R2-S3,
* from 24.4 before 24.4R2-S1,
* from 25.2 before 25.2R1-S1, 25.2R2.
Metrics
Affected Vendors & Products
References
History
Fri, 23 Jan 2026 19:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Juniper
Juniper junos Juniper mx10004 Juniper mx10008 Juniper mx2008 Juniper mx2010 Juniper mx2020 Juniper mx204 Juniper mx240 Juniper mx304 Juniper mx480 Juniper mx960 Juniper srx1500 Juniper srx1600 Juniper srx2300 Juniper srx300 Juniper srx320 Juniper srx340 Juniper srx345 Juniper srx380 Juniper srx4100 Juniper srx4120 Juniper srx4200 Juniper srx4300 Juniper srx4600 Juniper srx4700 Juniper srx5400 Juniper srx5600 Juniper srx5800 |
|
| CPEs | cpe:2.3:h:juniper:mx10004:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx10008:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx2008:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx2010:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx2020:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx204:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx240:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx304:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx480:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:mx960:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx1500:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx1600:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx2300:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx300:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx320:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx340:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx345:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx380:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4100:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4120:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4200:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4300:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4600:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4700:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx5400:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx5600:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx5800:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r1-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r1-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r2-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r2-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s4:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s5:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s6:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s7:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s8:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3-s9:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.2:r3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r1-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r1-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r2-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r2-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s10:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s11:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s4:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s5:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s6:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s7:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s8:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3-s9:*:*:*:*:*:* cpe:2.3:o:juniper:junos:21.4:r3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r2-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r3-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r3-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r3-s3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r3-s4:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r3-s5:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r3-s6:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r3-s7:*:*:*:*:*:* cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:r2-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:r2-s3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:r2-s4:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.2:r2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r1-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2-s4:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2-s5:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r2-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r2-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:r1-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:r1-s3:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:r2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:25.2:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:25.2:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:25.2:r2:*:*:*:*:*:* |
|
| Vendors & Products |
Juniper
Juniper junos Juniper mx10004 Juniper mx10008 Juniper mx2008 Juniper mx2010 Juniper mx2020 Juniper mx204 Juniper mx240 Juniper mx304 Juniper mx480 Juniper mx960 Juniper srx1500 Juniper srx1600 Juniper srx2300 Juniper srx300 Juniper srx320 Juniper srx340 Juniper srx345 Juniper srx380 Juniper srx4100 Juniper srx4120 Juniper srx4200 Juniper srx4300 Juniper srx4600 Juniper srx4700 Juniper srx5400 Juniper srx5600 Juniper srx5800 |
Fri, 16 Jan 2026 17:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Fri, 16 Jan 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Juniper Networks
Juniper Networks junos Os |
|
| Vendors & Products |
Juniper Networks
Juniper Networks junos Os |
Thu, 15 Jan 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in the SIP application layer gateway (ALG) of Juniper Networks Junos OS on SRX Series and MX Series with MX-SPC3 or MS-MPC allows an unauthenticated network-based attacker sending specific SIP messages over TCP to crash the flow management process, leading to a Denial of Service (DoS). On SRX Series, and MX Series with MX-SPC3 or MS-MPC service cards, receipt of multiple SIP messages causes the SIP headers to be parsed incorrectly, eventually causing a continuous loop and leading to a watchdog timer expiration, crashing the flowd process on SRX Series and MX Series with MX-SPC3, or mspmand process on MX Series with MS-MPC. This issue only occurs over TCP. SIP messages sent over UDP cannot trigger this issue. This issue affects Junos OS on SRX Series and MX Series with MX-SPC3 and MS-MPC: * all versions before 21.2R3-S10, * from 21.4 before 21.4R3-S12, * from 22.4 before 22.4R3-S8, * from 23.2 before 23.2R2-S5, * from 23.4 before 23.4R2-S6, * from 24.2 before 24.2R2-S3, * from 24.4 before 24.4R2-S1, * from 25.2 before 25.2R1-S1, 25.2R2. | |
| Title | Junos OS: SRX Series, MX Series with MX-SPC3 or MS-MPC: Receipt of multiple specific SIP messages results in flow management process crash | |
| Weaknesses | CWE-835 | |
| References |
| |
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: juniper
Published: 2026-01-15T20:19:22.158Z
Updated: 2026-01-16T16:26:02.071Z
Reserved: 2026-01-05T17:32:48.710Z
Link: CVE-2026-21905
Updated: 2026-01-16T16:25:58.792Z
Status : Analyzed
Published: 2026-01-15T21:16:05.990
Modified: 2026-01-23T19:40:26.687
Link: CVE-2026-21905
No data.