How severe is CVE-2023-26431?

CVE-2023-26431 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2023-26431 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-26431?

CVE-2023-26431 primarily affects Open-xchange Open-xchange Appsuite Backend. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-26431?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-26431 published?

CVE-2023-26431 was published on 2023-06-20 and last updated on 2026-06-17.

CVE-2023-26431

CVE-2023-26431 is a medium-severity vulnerability in Open-xchange Open-xchange Appsuite Backend with a CVSS 3.x base score of 5.0. 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-918.

Key facts

Severity: Medium (CVSS 3.x base score 5.0)
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-918
Affected product: Open-xchange Open-xchange Appsuite Backend
Published: 2023-06-20
Last modified: 2026-06-17

Description

IPv4-mapped IPv6 addresses did not get recognized as "local" by the code and a connection attempt is made. Attackers with access to user accounts could use this to bypass existing deny-list functionality and trigger requests to restricted network infrastructure to gain insight about topology and running services. We now respect possible IPV4-mapped IPv6 addresses when checking if contained in a deny-list. No publicly available exploits are known.

Frequently asked questions

What is CVE-2023-26431?: IPv4-mapped IPv6 addresses did not get recognized as "local" by the code and a connection attempt is made. Attackers with access to user accounts could use this to bypass existing deny-list functionality and trigger requests to restricted network infrastructure to gain insight about topology and running services. We now respect possible IPV4-mapped IPv6 addresses when checking if contained in a deny-list. No publicly available exploits are known.
How severe is CVE-2023-26431?: CVE-2023-26431 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2023-26431 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-26431?: CVE-2023-26431 primarily affects Open-xchange Open-xchange Appsuite Backend. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-26431?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-26431 published?: CVE-2023-26431 was published on 2023-06-20 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:open-xchange:open-xchange_appsuite_backend:*:*:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite_backend:7.10.6:*:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite_backend:7.10.6:revision_39:*:*:*:*:*:*

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