CVE-2025-52955: Juniper Networks Junos OS · Incorrect Calculation of Buffer Size
Affects Juniper Networks Junos OSSource CVE Database V5
Not known to be exploited · CVSS 6.5 Medium.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Juniper Networks Junos OS | Affected
| Fixed in– |
AI-suggested
1. Immediate mitigation should include network segmentation and strict access control to limit adjacency to trusted devices only, reducing the attack surface. 2. Monitor network interfaces for frequent logical interface flapping and investigate unusual update traffic patterns targeting jflow/sflow modules. 3. Apply vendor-released patches or updates as soon as they become available to address the buffer size calculation flaw. 4. Implement rate limiting or filtering on routing protocol update messages where possible to prevent flooding with malicious updates. 5. Use network anomaly detection tools to identify repeated rpd crashes or unusual routing daemon restarts indicative of exploitation attempts. 6. Maintain up-to-date inventory of Junos OS versions deployed and prioritize upgrades for affected versions. 7. Engage with Juniper support for any available workarounds or hotfixes if immediate patching is not feasible. 8. Conduct regular vulnerability assessments and penetration tests focusing on network layer protocols to detect potential exploitation vectors.
Description
An Incorrect Calculation of Buffer Size vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a memory corruption that leads to a rpd crash. When the logical interface using a routing instance flaps continuously, specific updates are sent to the jflow/sflow modules. This results in memory corruption, leading to an rpd crash and restart. Continued receipt of these specific updates will cause a sustained Denial of Service condition. This issue affects Junos OS: * All versions before 21.2R3-S9, * All versions of 21.4, * All versions of 22.2, * from 22.4 before 22.4R3-S7, * 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 of 21.2-EVO, * All versions of 21.4-EVO, * All versions of 22.2-EVO, * from 22.4 before 22.4R3-S7-EVO, * from 23.2 before 23.2R2-S3-EVO, * from 23.4 before 23.4R2-S4-EVO, * from 24.2 before 24.2R2-EVO.