Use After Free in Juniper Junos
CVE-2025-52946
A Use After Free vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Juniper Networks Junos OS Evolved allows an attacker sending a BGP update with a specifically malformed AS PATH to cause rpd to crash, resulting in a Denial of Service (DoS). Continuous receipt of the malformed AS PATH attribute will cause a sustained DoS condition. On all Junos OS and Junos OS Evolved platforms, the rpd process will crash and restart when a specifically malformed AS PATH is received within a BGP update and traceoptions are enabled. This issue only affects systems with BGP traceoptions enabled and requires a BGP session to be already established. Systems without BGP traceoptions enabled are not impacted by this issue. This issue affects: Junos OS: * All versions before 21.2R3-S9, * all versions of 21.4, * from 22.2 before 22.2R3-S6, * from 22.4 before 22.4R3-S5, * from 23.2 before 23.2R2-S3, * from 23.4 before 23.4R2-S4, * from 24.2 before 24.2R2; Junos OS Evolved: * All versions before 22.4R3-S5-EVO, * from 23.2-EVO before 23.2R2-S3-EVO, * from 23.4-EVO before 23.4R2-S4-EVO, * from 24.2-EVO before 24.2R2-EVO. This is a more complete fix for previously published CVE-2024-39549 (JSA83011).
Vulnerability class: Use-After-Free
EPSS: 0.004 (36.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Juniper Junos — versions 21.2, 21.4, 22.2
- Juniper Junos_os_evolved — versions 22.4, 23.2, 23.4
- Juniper Networks Junos Os — versions 0, 21.4, 22.2
- Juniper Networks Junos Os Evolved — versions 0, 23.2-EVO, 23.4-EVO
Weakness classification (CWE)
References
- sirt@juniper.net (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-52946?
- CVE-2025-52946 is a high-severity vulnerability in Juniper Junos, classified under Use After Free. CVSS score: 7.5/10. Published 2025-07-11.
- How severe is CVE-2025-52946?
- High severity. CVSS v3 base score is 7.5 out of 10.