High priorityDisclosed

Advisory · CVE-2026-102024

Integer overflow in Junos rpd lets a BGP peer crash it with extended next-hop tunneling

An integer overflow or wraparound vulnerability in the routing daemon (rpd) of Junos OS and Junos OS Evolved lets an authenticated BGP peer cause a denial of service via BGP route updates when extended-nexthop-tunnel is enabled. Juniper rates it CVSS 4.0 8.7 (CVSS 3.1 7.5).

Advisory published October 14, 2026Independent summary
Vendor
Juniper Networks
Product
Junos OS
Identifier / CWE
CVE-2026-102024
CWE-190
Action timing
Immediate
ELI5

Explain it like I’m five

A tunnel attribute makes route arithmetic wrap, and the daemon crashes on the result.

SIMPLIFIED_ATTACK_PATH03 STEPS
  1. 01Trigger input

    An attacker sends the crafted protocol traffic described for CVE-2026-102024.

  2. 02Weakness trips

    The daemon mishandles the input through the integer overflow or wraparound weakness.

  3. 03Impact lands

    The routing or control-plane daemon crashes or misbehaves as described.

What happened

Juniper disclosed CVE-2026-102024 in its October 2026 security release: an integer overflow or wraparound vulnerability (CWE-190) in rpd. An authenticated BGP peer can deny service via BGP route updates when extended-nexthop-tunnel is enabled.

Juniper’s JSA112187 lists the affected service releases and the October 2026 service release thresholds that carry the fix. Match your exact release to the advisory rather than guessing here.

What to do

  1. Inventory every Junos OS deployment, including test, training, and individually managed instances.
  2. Apply the vendor fix or upgrade exactly as directed in the linked vendor bulletin or advisory.
  3. Restrict network access to Junos OS while remediation is underway, especially for internet-facing instances.
  4. Review application and server logs for rpd crashes on devices with extended-nexthop-tunnel enabled, following peer route updates.
  5. Check for accounts, content, or configuration created outside normal change processes, and rotate exposed credentials where access cannot be ruled out.
  6. Verify the deployed version or patch level after remediation.

Management note

Another feature-gated rpd crash. The fix is the same release; the audit is knowing where the feature runs.