"HPE Telco Service Orchestrator CVE-2025-31651 (CVSS 9.8): Critical Flaw for Carrier Networks"
HPE has published a Product Security Incident Response Team (PSIRT) bulletin covering multiple vulnerabilities in HPE Telco Service Orchestrator (TSO), the carrier-grade orchestration platform used to design and automate network and cloud services. The most severe issue, CVE-2025-31651, carries a CVSS v3.1 base score of 9.8 (Critical). This post explains what is affected, how serious it is, and the exact steps to remediate.
What happened
CVE-2025-31651 is not a flaw in HPE's own code. It is a vulnerability in Apache Tomcat, the open-source servlet container that HPE Telco Service Orchestrator bundles as part of its application stack. Because TSO ships with an affected Tomcat version, HPE picked the issue up in its software and issued a PSIRT advisory directing customers to a fixed release.
The underlying weakness is classified as Improper Neutralization of Escape, Meta, or Control Sequences. In practical terms, for a subset of uncommon Tomcat rewrite-rule configurations, a specially crafted request could bypass some of those rewrite rules. Where those rules are used to enforce security constraints (for example, restricting access to certain paths), the constraint could be circumvented.
The same HPE bulletin also addresses a second, related Tomcat issue, CVE-2025-31650, a denial-of-service flaw. Both are resolved by the same HPE update.
Affected products and versions
The CVE applies to Apache Tomcat upstream, and the practical impact for HPE customers is in the HPE Telco Service Orchestrator product that embeds it.
| Product | Affected | Fixed |
|---|---|---|
| HPE Telco Service Orchestrator | Versions prior to v5.3.2 | v5.3.2 or later |
| Apache Tomcat 11.x (upstream component) | 11.0.0-M1 through 11.0.5 | 11.0.6 |
| Apache Tomcat 10.1.x (upstream component) | 10.1.0-M1 through 10.1.39 | 10.1.40 |
| Apache Tomcat 9.0.x (upstream component) | 9.0.0.M1 through 9.0.102 | 9.0.104 |
The Tomcat rows are shown for reference. For HPE Telco Service Orchestrator customers, the supported remediation path is HPE's own TSO 5.3.2 release rather than swapping the bundled Tomcat manually. The HPE advisory is published as PSIRT bulletin HPESBNW04872 ("HPE Telco Service Orchestrator software, Multiple Vulnerabilities").
How serious is it
CVE-2025-31651 is rated 9.8 Critical by the National Vulnerability Database, with the vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. That vector means it is network-exploitable, has low attack complexity, and requires no privileges and no user interaction, with high impact to confidentiality, integrity, and availability.
A caveat worth keeping in perspective: Apache's own description notes that the bypass only applies to a subset of unlikely rewrite-rule configurations. The 9.8 score reflects the worst-case impact when such a vulnerable configuration is in use; not every deployment will be exposed in the same way. The companion issue, CVE-2025-31650, is a denial-of-service flaw rated 7.5 (High) caused by incomplete clean-up of certain invalid HTTP requests, which can lead to an OutOfMemoryException.
On exploitation status: as of publication, CVE-2025-31651 is not listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, and we have found no public reporting of active exploitation in the wild. That can change, and the critical rating plus the orchestration platform's central role in a carrier environment make prompt patching the prudent course. Treat the absence of known exploitation as a reason to plan calmly, not a reason to defer.
Am I exposed?
You should assume relevance and verify if any of the following are true:
- You run HPE Telco Service Orchestrator at any version below 5.3.2.
- Your TSO instance, or its Tomcat-fronted web interfaces, is reachable from networks beyond a tightly controlled management segment.
- You rely on Tomcat rewrite rules to enforce access or path-based security constraints — this is the specific condition CVE-2025-31651 can undermine.
To confirm, check your installed TSO version against 5.3.2 and review whether security-relevant rewrite rules are configured. If TSO sits behind a reverse proxy or WAF that performs its own path normalization and access control, that may reduce but does not eliminate the exposure, and it is not a substitute for the vendor fix.
How to fix it
- Upgrade to HPE Telco Service Orchestrator v5.3.2 or later. This is HPE's supported remediation for both CVE-2025-31651 and CVE-2025-31650. The update is distributed through HPE's licensing portal (myenterpriselicense.hpe.com / HPE Software Center).
- Review the official advisory. Read HPE PSIRT bulletin HPESBNW04872 in full for any deployment-specific notes before upgrading.
- Apply interim mitigations if you cannot patch immediately. Restrict network access to the TSO management interfaces so they are reachable only from trusted administrative networks; audit and, where possible, remove or tighten Tomcat rewrite rules that enforce security constraints; and place TSO behind a reverse proxy or WAF that normalizes request paths. These reduce the attack surface but are stopgaps, not replacements for v5.3.2.
- Validate after upgrading. Confirm the running version, re-test any rewrite-rule-based access controls, and monitor logs for anomalous requests during the transition.
For organizations running a fleet of carrier or OSS workloads, treat this as a coordinated maintenance event: inventory every TSO instance, schedule the upgrade through change control, and verify each node rather than assuming a single environment is representative.
How Uniqcli helps
Uniqcli is an authorized reseller for HPE, HPE Aruba Networking, and HPE Juniper Networking, and we work daily with US federal, SLED, healthcare, and enterprise teams on exactly this kind of remediation.
- Assess exposure. We can help you inventory HPE Telco Service Orchestrator instances, confirm versions against the fixed 5.3.2 baseline, and identify which deployments use the rewrite-rule configurations that CVE-2025-31651 targets.
- Source patched software and replacement hardware. Whether you need the licensed TSO update path or are refreshing the underlying server, storage, or networking platform as part of the same maintenance window, we can quote and supply through compliant channels.
- Support the upgrade. From planning the change window to validating the fix, we help your team get to a remediated state with minimal disruption.
- Procurement built for the public sector. We support TAA-compliant, GSA, and SEWP procurement so federal and SLED buyers can acquire patched software and hardware on the contract vehicles they already use.
If you operate HPE Telco Service Orchestrator and want help confirming exposure or planning the move to v5.3.2, reach out to the Uniqcli team.
Sources
- HPE PSIRT bulletin (HPE Telco Service Orchestrator, Multiple Vulnerabilities) — support.hpe.com
- CVE-2025-31651 Detail — NVD
- CVE-2025-31650 Detail — NVD
- Múltiples vulnerabilidades en HPE Telco Service Orchestrator — CERT-PY
- Múltiples vulnerabilidades en Telco Service Orchestrator de HPE — INCIBE-CERT
- CISA Known Exploited Vulnerabilities Catalog
- HPE Issues Security Patch for StoreOnce Bug — The Hacker News