CVE-2025-52946 Junos OS and Junos OS Evolved: With traceoptions enabled, receipt of malformed AS PATH causes RPD crash
Attackers can crash the routing daemon via malformed BGP updates if traceoptions are enabled, causing denial of service on Juniper devices.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-52946?
CVE-2025-52946 is a high-severity use after free vulnerability in Juniper Junos, published on 11 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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).
Weakness: CWE-416
Which versions are affected by CVE-2025-52946?
It affects 2 products.
Products include Juniper Junos, Juniper Junos Os Evolved.
How do I fix CVE-2025-52946?
No fix has been published for CVE-2025-52946 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-52946 being exploited?
There is no known exploitation of CVE-2025-52946 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-2f8g-7hcr-fj76.