Junos OS: Buffer overflow in SDK service allows denial of service or compromise
Summary
A classic buffer overflow in the SDK service process of Juniper Junos OS can be triggered by specially crafted packets sent by an unauthenticated attacker. Successful exploitation can crash the SDK service or compromise the Routing Engine, the control plane of the device. The vulnerable state requires that the SDK service and a JDAF routing instance are both enabled, which is not the default configuration.
Affected
- Junos OS 0 to < 23.2R2-S7.7
- Junos OS 23.4 to < 23.4R2-S8.13
- Junos OS 24.2 to < 24.2R2-S5.5
- Junos OS 24.4 to < 24.4R2-S5
- Junos OS 25.2 to < 25.2R2-S2
- Junos OS 25.4 to < 25.4R1-S3
- Junos OS 26.2 to < 26.2R1-S2
- Required configuration: system processes sdk-service enable and services jdaf routing-instances
Fixed in
- Junos OS 23.2R2-S7.7
- Junos OS 23.4R2-S8.13
- Junos OS 24.2R2-S5.5
- Junos OS 24.4R2-S5
- Junos OS 25.2R2-S2
- Junos OS 25.4R1-S3 and 25.4R2
- Junos OS 26.2R1-S2 and 26.2R2
- Junos OS 26.4R1 and all subsequent releases
- Verify the versions against Juniper advisory JSA112188 before rollout.
Workaround
- Disable the SDK service (system processes sdk-service) if it is not required.
- If this is not feasible, restrict traffic to the SDK service port with firewall rules and remove JDAF routing instances from the configuration.
Exploitation
- Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
- No public proof-of-concept found.
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- EPSS about 0.30%.
Our recommendation
- Check whether any Junos device runs the SDK service together with JDAF routing instances.
- If so, upgrade to a fixed release listed in JSA112188, or disable the SDK service as an interim step.
- Restrict access to management and service ports to trusted networks.
- Re-check NVD and the Juniper advisory once NVD analysis is complete.
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-2026-102176 app.opencve.io
- VulnCheck/Vulners VULNRICHMENT CVE-2026-102176 vulners.com
- Strix CVE-2026-102176 www.strix.ai
- SecurityOnline: Juniper patches critical Junos OS vulnerabilities securityonline.info
- Canadian Centre for Cyber Security AV26-128 www.cyber.gc.ca
- JDAF routing-instances configuration reference www.juniper.net
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, 03:04.
Original description (NVD)
A Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in the SDK service process of Juniper Networks Junos OS allows an unauthenticated network attacker to cause a denial of service or compromise the Routing Engine by sending specific packets when the SDK service and a JDAF routing instance are enabled.
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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