Vulnerability · CVE-2025-52947
An Improper Handling of Exceptional Conditions vulnerability in route processing of Juniper Networks Junos OS on specific end-of-life (EOL) ACX Series platforms allows an attacker
Published Jul 11, 2025 · catalog updated Jul 11, 2025 · Juniper Networks Junos OS
Last checked Oct 29, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2025-52947. EPSS is 0.30%. Act only if a listed version of Juniper Networks Junos OS is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2026-102185 · High
- CVE-2026-102184 · High
- CVE-2026-102183 · High
- CVE-2026-102182 · Critical
- CVE-2026-102180 · High
- Severity
- High7.1
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.30%
- Remediation
- Version ranges on file
- Affected products
- vendor Juniper Networks Junos OS 0 <21.2R3-S9
An Improper Handling of Exceptional Conditions vulnerability in route processing of Juniper Networks Junos OS on specific end-of-life (EOL) ACX Series platforms allows an attacker to crash the Forwarding Engine Board (FEB) by flapping an interface, leading to a Denial of Service (DoS). On ACX1000, ACX1100, ACX2000, ACX2100, ACX2200, ACX4000, ACX5048, and ACX5096 devices, FEB0 will crash when the primary path port of the L2 circuit IGP (Interior Gateway Protocol) on the local device goes down. This issue is seen only when 'hot-standby' mode is configured for the L2 circuit. This issue affects J
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor Juniper Networks Junos OS 0 <21.2R3-S90 <21.2R3-S9
How to fix CVE-2025-52947
Upgrade
CVE-2025-52947 lists a fix boundary at 21.2R3-S9. Compare the installed build with that boundary before you change production.
Version check
Seen in 0 <21.2R3-S9
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2025-52947. EPSS is 0.30%. Act only if a listed version of Juniper Networks Junos OS is installed.
Which versions are affected?
Compare what you have installed with Juniper Networks Junos OS 0 <21.2R3-S9 0 <21.2R3-S9. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.30%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jul 11, 2025 · EUVD
Detected
An Improper Handling of Exceptional Conditions vulnerability in route processing of Juniper Networks Junos OS on specific end-of-life (EOL) ACX Series platforms allows an attacker to crash the Forwarding Engine Board (FEB) by flapping an interface, leading to a Denial of Service (DoS). On ACX1000, ACX1100, ACX2000, ACX2100, ACX2200, ACX4000, ACX5048, and ACX5096 devices, FEB0 will crash when the p
Jul 11, 2025 · EUVD
Updated
An Improper Handling of Exceptional Conditions vulnerability in route processing of Juniper Networks Junos OS on specific end-of-life (EOL) ACX Series platforms allows an attacker to crash the Forwarding Engine Board (FEB) by flapping an interface, leading to a Denial of Service (DoS). On ACX1000, ACX1100, ACX2000, ACX2100, ACX2200, ACX4000, ACX5048, and ACX5096 devices, FEB0 will crash when the p
Sources
- CVE.orgVulnerability recordCVE-2025-52947
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2025-52947
30-day exploitation probability 0.30%
first.org - EUVDVulnerability recordEUVD-2025-21140
An Improper Handling of Exceptional Conditions vulnerability in route processing of Juniper Networks Junos OS on specific end-of-life (EOL) ACX Series platforms allows an attacker to crash the Forwarding Engine Board (FEB) by flapping an interface, leading to a Denial of Service
euvd.enisa.europa.eu
References
Freshness
Last verified in this catalog Oct 29, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSOct 23, 2026
- CVE.orgOct 21, 2026
- EUVDOct 19, 2026