Detect Palo Alto Networks PAN-OS Out-of-bounds Write (CVE-2026-0300) in Splunk
Detects exploitation attempts targeting CVE-2026-0300, an out-of-bounds write vulnerability (CWE-787) in Palo Alto Networks PAN-OS. This vulnerability is actively exploited in the wild (CISA KEV) and may allow attackers to execute arbitrary code, crash the device, or escalate privileges on affected PAN-OS appliances. Detection focuses on anomalous management plane activity, unexpected process crashes, memory corruption indicators, and suspicious inbound traffic patterns targeting PAN-OS management interfaces.
MITRE ATT&CK
- Tactic
- Initial Access Execution Impact
SPL Detection Query
index=network OR index=firewall OR index=syslog earliest=-24h
| eval is_panos=if(vendor="Palo Alto Networks" OR sourcetype IN ("pan:firewall","pan:system","pan:threat","pan:traffic"), 1, 0)
| search is_panos=1
| eval exploit_signal=case(
match(message, "(?i)(out.of.bounds|memory corruption|segfault|core dump|stack smash|buffer overflow)"), "memory_corruption",
match(message, "(?i)(crash|fatal|abort|signal 11|sigsegv)"), "process_crash",
match(message, "(?i)(threat.*overflow|exploit|cve-2026-0300)"), "direct_exploit_indicator",
1=1, NULL()
)
| search exploit_signal=*
| stats count AS event_count, values(src_ip) AS source_ips, values(exploit_signal) AS signals, earliest(_time) AS first_seen, latest(_time) AS last_seen BY host, dest_ip
| eval duration_minutes=round((last_seen - first_seen) / 60, 2)
| where event_count >= 2
| eval cve="CVE-2026-0300"
| table _time, cve, host, dest_ip, source_ips, signals, event_count, duration_minutes, first_seen, last_seen
| sort -event_countSplunk detection for CVE-2026-0300 targeting PAN-OS devices. Searches PAN-OS sourcetypes for memory corruption, process crash, and direct exploit indicators, then correlates events by host and destination IP to surface multi-signal exploitation patterns.
Data Sources
Required Sourcetypes
False Positives & Tuning
- Authorized penetration testing engagements with active scanners targeting PAN-OS
- Legitimate software upgrade processes causing temporary process restarts logged as crashes
- High-cardinality alerting environments where threshold tuning has not been applied to management traffic
- Misconfigured logging pipelines that duplicate events and inflate event counts
Other platforms for CVE-2026-0300
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Simulate malformed HTTPS payload to PAN-OS management interface
Expected signal: PAN-OS threat logs should record an anomalous inbound connection; syslog may show a connection handling error or rate limit trigger on the management interface.
- Test 2Trigger PAN-OS management daemon crash simulation via process kill
Expected signal: PAN-OS system logs will record a process crash event for sslmgrd with signal 11 (SIGSEGV); watchdog restart will generate a subsequent SYSTEM log entry. Syslog forwarding will push these to the SIEM.
- Test 3Enumerate PAN-OS management interface exposure and version fingerprinting
Expected signal: PAN-OS management logs will record the inbound HTTPS requests from the test source IP. If threat prevention is enabled, reconnaissance-pattern requests may trigger a threat log entry.
Unlock Pro Content
Get the full detection package for CVE-2026-0300 including response playbook, investigation guide, and atomic red team tests.