CVE-2026-21905 is an 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. An unauthenticated attacker can trigger a Denial of Service (DoS) by sending specific TCP-based SIP messages, causing the flow management process to crash. This vulnerability has a CVSS score of 7.5 (HIGH), indicating a network-based attack with low complexity and high impact on availability. There is currently no evidence of active exploitation, public exploit code, or significant community discussion surrounding this CVE.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 0, < 21.2R3-S10CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 21.4, < 21.4R3-S12CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 22.4, < 22.4R3-S8CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 23.2, < 23.2R2-S5CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 23.4, < 23.4R2-S6CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* |
CVSS version used by this source: 4.0
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:C/RE:M/U:Amber
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