Affects Juniper SRX firewalls (widely deployed network infrastructure); can cause network-wide DoS and reboots impacting availability across organizations.
CVE-2026-57030
Race condition in Juniper SRX packet engine leading to DoS and reboots.
Is CVE-2026-57030 being exploited?
Not confirmed. CVE-2026-57030 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 0.38% probability of exploitation in the next 30 days.
How severe is CVE-2026-57030?
CVE-2026-57030 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-2026-57030?
Yes. A fix has been recorded for CVE-2026-57030. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-57030 affect?
CVE-2026-57030 affects Juniper SRX Series Junos OS 24.2 before 24.2R2-S3, Juniper SRX Series Junos OS 24.4 before 24.4R2-S1/S2, Juniper SRX Series Junos OS 25.2 before 25.2R1-S2 and 25.2R2. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-57030?
Upgrade SRX to the listed fixed Junos releases ASAP and monitor flow/session counters.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated network attacker can trigger race condition that creates persistent flows, causing forwarding to stop, flowd crash, and device reboot (DoS).
Immediate action required
- affected>= 24.2 and < 24.2R2-S3
- affected>= 24.4 and < 24.4R2-S1
- affected>= 25.2 and < 25.2R1-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.