Juniper Junos OS SRX: Heap-based buffer overflow in SVR component

Summary

A heap-based buffer overflow in the Secure Vector Routing (SVR) component of Junos OS on SRX Series firewalls can be triggered by malformed IPv4 packets. The attack requires no authentication, but only affects interfaces configured for SVR. The main impact is a crash of the packet-forwarding process, leading to denial of service. The advisory also states that confidentiality and integrity could potentially be compromised, but remote code execution is not stated.

Affected

• Junos OS 0 to before 23.2R2-S7.7
• Junos OS 23.4 to before 23.4R2-S8.13
• Junos OS 24.2 to before 24.2R2-S5.5
• Junos OS 24.4 to before 24.4R2-S5
• Junos OS 25.2 to before 25.2R2-S2
• Junos OS 25.4 to before 25.4R1-S3
• Junos OS 26.2 to before 26.2R1-S2
• Only exploitable on interfaces with services vector-routing configured. Default configuration is unaffected.
• Version ranges taken from the CVE record; verify against JSA112186.

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 or 25.4R2
• Junos OS 26.2R1-S2 or 26.2R2
• Junos OS 26.4R1 and all subsequent releases

Workaround

• No known workarounds according to the CVE record. Check the workarounds section of JSA112186.
• Limit which sources can send traffic to SVR-enabled interfaces, or disable SVR where it is not required (administrative measure, not a vendor fix).

Exploitation

• Juniper SIRT is not aware of any malicious exploitation.
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• EPSS estimates a 0.47% chance of exploitation within 30 days.
• No public proof of concept found in the sources checked. Not found in the CISA KEV catalogue in the results checked.
• Juniper's advisory metadata lists the discovery as internal.

Our recommendation

• Inventory all SRX devices and their Junos OS releases.
• Check whether services vector-routing is configured (show configuration services vector-routing).
• Compare releases with the fixed versions in JSA112186 and schedule the upgrade, prioritising internet-facing devices and devices with SVR enabled.
• If SVR is not needed, disable it. If patching is delayed, restrict which sources can reach SVR-enabled interfaces.
• Monitor for unexpected crashes or restarts of the packet-forwarding process (srxpfe).

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Juniper Security Advisory JSA112186 supportportal.juniper.net
• OpenCVE: CVE-2026-101950 app.opencve.io
• VulDB: CVE-2026-101950 vuldb.com
• Vulners VulnCheck/VulnRichment: CVE-2026-101950 vulners.com
• Strix: CVE-2026-101950 www.strix.ai

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 31 Oct 2026, 02:01.