How severe is CVE-2023-40256?

CVE-2023-40256 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-40256 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-40256?

CVE-2023-40256 primarily affects Veritas Netbackup Snapshot Manager. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-40256?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2023-40256 published?

CVE-2023-40256 was published on 2023-08-11 and last updated on 2026-06-17.

CVE-2023-40256

CVE-2023-40256 is a critical-severity vulnerability in Veritas Netbackup Snapshot Manager with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (25th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Veritas Netbackup Snapshot Manager
Published: 2023-08-11
Last modified: 2026-06-17

Description

A vulnerability was discovered in Veritas NetBackup Snapshot Manager before 10.2.0.1 that allowed untrusted clients to interact with the RabbitMQ service. This was caused by improper validation of the client certificate due to misconfiguration of the RabbitMQ service. Exploiting this impacts the confidentiality and integrity of messages controlling the backup and restore jobs, and could result in the service becoming unavailable. This impacts only the jobs controlling the backup and restore activities, and does not allow access to (or deletion of) the backup snapshot data itself. This vulnerability is confined to the NetBackup Snapshot Manager feature and does not impact the RabbitMQ instance on the NetBackup primary servers.

Frequently asked questions

What is CVE-2023-40256?: A vulnerability was discovered in Veritas NetBackup Snapshot Manager before 10.2.0.1 that allowed untrusted clients to interact with the RabbitMQ service. This was caused by improper validation of the client certificate due to misconfiguration of the RabbitMQ service. Exploiting this impacts the confidentiality and integrity of messages controlling the backup and restore jobs, and could result in the service becoming unavailable. This impacts only the jobs controlling the backup and restore activities, and does not allow access to (or deletion of) the backup snapshot data itself. This vulnerability is confined to the NetBackup Snapshot Manager feature and does not impact the RabbitMQ instance on the NetBackup primary servers.
How severe is CVE-2023-40256?: CVE-2023-40256 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-40256 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-40256?: CVE-2023-40256 primarily affects Veritas Netbackup Snapshot Manager. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-40256?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-40256 published?: CVE-2023-40256 was published on 2023-08-11 and last updated on 2026-06-17.

References

https://www.veritas.com/content/support/en_US/security/VTS23-011

Affected products (9)

cpe:2.3:a:veritas:netbackup_snapshot_manager:*:*:*:*:*:*:*:*
cpe:2.3:a:veritas:netbackup_snapshot_manager:9.0:*:*:*:*:*:*:*
cpe:2.3:a:veritas:netbackup_snapshot_manager:9.1:*:*:*:*:*:*:*
cpe:2.3:a:veritas:netbackup_snapshot_manager:9.1.0.1:*:*:*:*:*:*:*
cpe:2.3:a:veritas:netbackup_snapshot_manager:10.0:*:*:*:*:*:*:*
cpe:2.3:a:veritas:netbackup_snapshot_manager:10.0.0.1:-:*:*:*:*:*:*
cpe:2.3:a:veritas:netbackup_snapshot_manager:10.1:*:*:*:*:*:*:*
cpe:2.3:a:veritas:netbackup_snapshot_manager:10.1.1:-:*:*:*:*:*:*
cpe:2.3:a:veritas:netbackup_snapshot_manager:10.2:*:*:*:*:*:*:*

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