CVE-2026-42613 in ArcSight ESM: Patch and Mitigate
CVE-2026-42613 is a high-severity denial-of-service flaw in OpenText Cybersecurity ArcSight Enterprise Security Manager Platform. The issue allows an unauthenticated remote attacker to trigger session process memory exhaustion, potentially disrupting service for all users. If your organization relies on ArcSight ESM for alerting, correlation, and analyst workflows, this is not just an application outage risk. It is also a visibility and operations risk that can slow incident response at the wrong time.
For broader hardening guidance around central security tooling, see our related content on siem hardening best practices and vulnerability prioritization for security teams.
Vulnerability at a Glance
| Field | Value |
|---|---|
| CVE ID | CVE-2026-42613 |
| CVSS | 7.5 High (CVSS v3.1) |
| Attack vector | Network (remote) |
| Auth required | None |
| Patch status | Yes |
| CWE | CWE-400 Uncontrolled Resource Consumption |
| Impact | Denial of service caused by session process memory exhaustion |
| Vendor/Product | OpenText Cybersecurity ArcSight Enterprise Security Manager Platform |
| Fixed version | 7.8.0.3004 or later |
The vendor and NVD describe the issue as uncontrolled resource consumption in the ArcSight ESM session process. In practical terms, the flaw can exhaust process memory and make the platform unstable or unavailable.
What Is CVE-2026-42613?
CVE-2026-42613 is an uncontrolled resource consumption flaw in the session process of OpenText Cybersecurity ArcSight Enterprise Security Manager Platform. The weakness maps to CWE-400, which covers software that does not properly limit finite resources such as memory, CPU, file handles, or threads.
In this case, the affected resource is process memory. According to the available primary sources, an unauthenticated remote attacker can trigger memory exhaustion in the session process, resulting in denial of service for users of the platform. The published CVSS vector reflects this availability-focused impact: confidentiality and integrity are not reported as affected, while availability impact is High.
From a defender’s perspective, the risk is operationally significant because ArcSight ESM is central to monitoring and response. Even without code execution or data theft, a remotely reachable unauthenticated DoS issue in a SIEM platform deserves rapid triage and remediation.
It is also important not to overstate the issue. The consulted sources do not say this vulnerability enables privilege escalation, arbitrary code execution, event tampering, or data access. Based on the current evidence, CVE-2026-42613 should be treated as an availability-focused flaw.
Who Is Affected?
The affected product is OpenText Cybersecurity ArcSight Enterprise Security Manager Platform. The published affected range is clear: version 7.8.0.3003 and earlier. The vendor states the issue is fixed in version 7.8.0.3004, and the recommended remediation is to upgrade to 7.8.0.3004 or later.
Any ArcSight ESM deployment running 7.8.0.3003 or older should be considered vulnerable until confirmed otherwise. That review should include:
- Production environments
- Development and test systems
- Disaster recovery instances
- Lab or staging deployments
- Any secondary instances reachable from internal networks
This vulnerability is especially relevant where ArcSight management components are broadly exposed internally or, in worse cases, reachable from the internet. Because the published attack requirements are network reachability only and no authentication, unnecessary exposure materially increases risk.
For SOC teams and MSSPs, the impact can be larger than “just DoS” suggests. If ArcSight ESM becomes unstable, analysts may lose dashboard access, session reliability, and correlation visibility during an active investigation.
CVSS Score Breakdown
CVE-2026-42613 has a CVSS v3.1 base score of 7.5 (High) with vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Here is what that means in practice:
| Metric | Value | Meaning |
|---|---|---|
| Attack Vector | AV:N | Exploitable over the network |
| Attack Complexity | AC:L | No specialized conditions described |
| Privileges Required | PR:N | No account or prior access needed |
| User Interaction | UI:N | No victim action required |
| Scope | S:U | Impact remains within the vulnerable product |
| Confidentiality | C:N | No confirmed confidentiality impact |
| Integrity | I:N | No confirmed integrity impact |
| Availability | A:H | High availability impact due to memory exhaustion |
The most important factors for prioritization are:
- AV:N: the issue is remotely reachable
- PR:N: no credentials are required
- A:H: the availability impact is severe
That combination makes this a high-priority patching candidate, especially for organizations that depend on ArcSight ESM for daily detection and response operations.
Exploitation Status
Based strictly on the consulted sources, there is no verified public proof of concept for CVE-2026-42613 at this time. The NVD references and vendor bulletin reviewed do not point to public exploit code.
There is also no confirmed statement of in-the-wild exploitation in the cited sources. Neither the NVD entry nor the reviewed OpenText bulletin states that attackers are actively exploiting the vulnerability in production environments.
Still, defenders should not treat “no public PoC” as “low risk.” The issue is described as:
- Remote
- Unauthenticated
- Low complexity
Those characteristics make private reproduction plausible. A sound defensive position is to assume the flaw is practically exploitable by capable attackers while avoiding unsupported claims about active exploitation.
How to Detect It
The first step is version identification. Determine whether any ArcSight ESM instances are running 7.8.0.3003 or earlier. If your asset inventory does not track ArcSight versions reliably, validate directly on the host or through your standard application administration process.
The second step is behavior-based monitoring. Since the documented impact is session process memory exhaustion, defenders should watch for:
- Abnormal memory growth in ArcSight-related processes
- Service instability
- Process crashes
- Repeated restart events
- User reports of session failures or widespread access issues
The vendor advisory does not provide a canonical detection signature in the cited materials, so practical detection should focus on host telemetry and service health indicators rather than a single log string.
A useful approach is to correlate inbound traffic to ArcSight ESM services with sudden spikes in process memory use or degraded responsiveness. If you have EDR or host telemetry, look for resident memory spikes, out-of-memory conditions, or service restart loops.
Example Linux commands for initial hunting:
# Identify high-memory ArcSight-related processes
ps aux --sort=-%mem | grep -i arcsight
# Check for OOM-killer activity or memory pressure indicators
dmesg -T | egrep -i 'out of memory|oom-killer|killed process'
# Review recent service failures and restarts on systemd-based hosts
journalctl -S -24h | egrep -i 'arcsight|session|memory|oom|killed|restart'
If your team wants better endpoint visibility on servers involved in monitoring infrastructure, a trusted security tool can help with system hygiene and incident triage. For example, Get Malwarebytes → may be worth evaluating where it fits your server monitoring and investigation workflow.
A generic SIEM query could look for repeated restarts or OOM events on hosts tagged as ArcSight ESM servers:
(host_role="arcsight_esm" AND (
message CONTAINS "Out of memory" OR
message CONTAINS "oom-killer" OR
message CONTAINS "Killed process" OR
message CONTAINS "restart"
))
Because the consulted sources do not publish a vendor-approved IDS signature, defenders should assume there is no authoritative network detection pattern available yet from those references.
Mitigation and Patching
The primary remediation is straightforward: upgrade OpenText Cybersecurity ArcSight Enterprise Security Manager Platform to version 7.8.0.3004 or later. Systems running 7.8.0.3003 and earlier should be treated as vulnerable until the upgrade is completed and verified.
If you use formal change control, specify the target version precisely as 7.8.0.3004 or later. Avoid vague wording like “apply latest patch,” since precise versioning helps with auditability and validation.
If you cannot patch immediately, reduce exposure as an interim measure. Because the vulnerability is remote and unauthenticated, restrict access to ArcSight management and session-related interfaces to trusted administrative networks only. At a minimum:
- Remove internet exposure if present
- Limit inbound access with segmentation controls
- Apply host-based firewall restrictions where feasible
- Increase monitoring on ESM hosts for memory pressure and restart events
Example temporary control using iptables:
# Example: allow trusted admin subnet, then deny others to the ArcSight service port
iptables -A INPUT -p tcp -s 10.20.30.0/24 --dport PORT -j ACCEPT
iptables -A INPUT -p tcp --dport PORT -j DROP
Example with firewalld:
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="10.20.30.0/24" port protocol="tcp" port="PORT" accept'
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" port protocol="tcp" port="PORT" drop'
firewall-cmd --reload
These are workarounds, not fixes. Replace PORT with the actual ArcSight-exposed service port used in your environment.
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Recommended Response Plan
Security teams handling CVE-2026-42613 should take the following actions in order:
- Inventory ArcSight ESM instances and identify versions.
- Flag any system on 7.8.0.3003 or earlier as vulnerable.
- Upgrade to 7.8.0.3004 or later as the primary fix.
- Restrict network access to trusted administration paths if patching is delayed.
- Monitor for memory exhaustion symptoms, OOM events, and restart loops.
- Review analyst reports for session instability or broad platform access issues.
- Document remediation status for production, DR, and non-production environments.
This is a manageable issue if handled quickly, but one that can have outsized operational impact if neglected.
References
| Source | URL | Notes |
|---|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2026-42613 | Authoritative CVE record, CVSS score/vector, description, and references |
| OpenText Security Bulletin | https://www.opentext.com/support/security-bulletins#Arcsight_ESM_Platform_session_process_memory_exhaustion_denial_of_service_vulnerability | Vendor-confirmed affected versions, impact, and fixed version |
| OpenText/Micro Focus Support Article Reference | https://portal.microfocus.com/s/article/KM000038871?language=en_US | Vendor support portal reference cited by NVD |
The NVD entry confirms the key technical and scoring details: CVSS 7.5, vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, remote unauthenticated trigger conditions, and an availability-focused impact. The vendor bulletin provides the core remediation guidance: upgrade to ArcSight Enterprise Security Manager Platform 7.8.0.3004 or later.
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