Skip to main content
VulnerabilityPublished

CVE-2025-52958: Juniper Networks Junos OS · Reachable Assertion

Affects Juniper Networks Junos OSSource CVE Database V5

0

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score
5.3Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Jul 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Juniper Networks Junos OSAffected
  • 0 – 24.2
5 affected builds
Fixed in–

AI-suggested

  1. Immediate application of Juniper's security patches once available for the affected Junos OS and Junos OS Evolved versions is the primary mitigation step. Organizations should monitor Juniper's official advisories and update to fixed releases (e.g., 22.2R3-S6 or later).
  2. If patching is not immediately possible, disable route validation temporarily if feasible, as the vulnerability is triggered when route validation is enabled during BGP session establishment.
  3. Implement network segmentation and strict access controls to limit adjacency to routing devices only to trusted management and peer devices, reducing the risk of an attacker gaining adjacency.
  4. Monitor BGP session stability and rpd process health using network monitoring tools and Junos OS telemetry to detect abnormal crashes or restarts promptly.
  5. Employ anomaly detection to identify unusual BGP session failures or repeated connection attempts that could indicate exploitation attempts.
  6. Harden internal network security to prevent unauthorized devices from gaining adjacency to routing infrastructure, including strong authentication and network access controls.
  7. Conduct regular vulnerability assessments and penetration testing focused on network infrastructure to identify and remediate exposure to this and similar vulnerabilities.

Description

A Reachable Assertion vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause a Denial of Service (DoS).On all Junos OS and Junos OS Evolved devices, when route validation is enabled, a rare condition during BGP initial session establishment can lead to an rpd crash and restart. This occurs specifically when the connection request fails during error-handling scenario. Continued session establishment failures leads to a sustained DoS condition.  This issue affects Junos OS: * All versions before 22.2R3-S6, * from 22.4 before 22.4R3-S6, * 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 22.2R3-S6-EVO, * from 22.4 before 22.4R3-S6-EVO, * from 23.2 before 23.2R2-S3-EVO, * from 23.4 before 23.4R2-S4-EVO, * from 24.2 before 24.2R2-EVO.

References

Community reviews

Loading reviews…