Junos OS: Stack-based buffer overflow in dot1x daemon via ICCP peer
Summary
A stack-based buffer overflow in the dot1x daemon (dot1xd) of Junos OS devices operating as Junos Fusion Aggregation Devices can be triggered by an adjacent attacker who acts as the configured ICCP peer. Successful exploitation can cause a denial of service and may allow code execution as root. The issue only occurs when dot1x synchronization is enabled in the required Fusion satellite topology.
Affected
- Junos OS: 0 to < 23.2R2-S7.7; 23.4 to < 23.4R2-S8.13; 24.2 to < 24.2R2-S5.5; 24.4 to < 24.4R2-S5; 25.2 to < 25.2R2-S2; 25.4 to < 25.4R1-S3; 26.2 to < 26.2R1-S2 (default configuration is unaffected)
- Junos OS Evolved: Unknown.
Fixed in
- Junos OS: 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 26.2R1-S2, and later releases (per CNA record; verify in Juniper advisory JSA112188)
- Junos OS Evolved: 23.2R2-S7.7-EVO, 23.4R2-S8.11-EVO, 24.2R2-S5.6-EVO, 24.4R2-S5-EVO, 25.2R2-S2-EVO, 25.4R1-S3-EVO, 26.2R1-S2-EVO, and later releases (per CNA record).
Workaround
- No known workarounds according to the CNA record.
- Mitigation not from a source: if Junos Fusion is used and dot1x synchronization is not needed, disable it.
Exploitation
- Juniper SIRT is not aware of any malicious exploitation.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- No public proof of concept found in the sources checked.
Our recommendation
- Check whether any Junos device operates as a Junos Fusion Aggregation Device with dot1x synchronization enabled. If not, no action is needed for this CVE.
- If yes, read advisory JSA112188, upgrade to the listed fixed release, or disable dot1x synchronization until the upgrade is possible.
- Restrict the ICCP peer relationship to known, trusted devices and keep management and control-plane networks segmented.
- Check other issues in the same October 2026 Juniper bulletin, especially internet-reachable J-Web flaws, with higher priority.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Juniper Security Advisory JSA112188 supportportal.juniper.net
- OpenCVE: CVE-2026-102069 app.opencve.io
- Vulners VulnRichment: CVE-2026-102069 vulners.com
- Strix: CVE-2026-102069 www.strix.ai
- Tenable Nessus plugin 372460 www.tenable.com
- SecurityOnline: Juniper patches critical Junos OS vulnerabilities securityonline.info
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 03:10.
Original description (NVD)
A Stack-based Buffer Overflow vulnerability in the dot1x daemon of Juniper Networks Junos OS devices operating as Junos Fusion Aggregation Devices allows an adjacent attacker acting as the configured ICCP peer to cause a denial of service and potentially execute code as root via. The issue is triggered when dot1x synchronization is enabled for the required Fusion satellite topology.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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