Unauthenticated network DoS against Juniper SRX firewall FPC can cause widespread network/service outage for organizations and providers using Junos SRX.
CVE-2026-102086
Unauthenticated DNS-path DoS in Juniper SRX causing FPC crash and device outage.
Is CVE-2026-102086 being exploited?
Not confirmed. CVE-2026-102086 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.37% probability of exploitation in the next 30 days.
How severe is CVE-2026-102086?
CVE-2026-102086 is rated High with a CVSS score of 8.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-102086?
Yes. A fix has been recorded for CVE-2026-102086. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-102086 affect?
CVE-2026-102086 affects Juniper Junos OS on SRX Series < 23.2R2-S7.7, 23.4 before 23.4R2-S8.13, 24.2 before 24.2R2-S5.5, 24.4 before 24.4R2-S4, and 2 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-102086?
Apply Juniper fixed releases immediately; restrict/monitor DNS flows and watch for FPC crashes.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote, unauthenticated network-based DoS: specially crafted DNS flows can crash FPC, causing SRX device/service outage.
Immediate action required
- affected< 23.2R2-S7.7
- affected>= 23.4 and < 23.4R2-S8.13
- affected>= 24.2 and < 24.2R2-S5.5
- affected>= 24.4 and < 24.4R2-S4
- affected>= 25.2 and < 25.2R2-S1
- affected>= 25.4 and < 25.4R1-S2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.