How severe is CVE-2023-26455?

CVE-2023-26455 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability low.

Is CVE-2023-26455 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-26455?

CVE-2023-26455 primarily affects Open-xchange Open-xchange Appsuite. In total, 43 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-26455?

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

When was CVE-2023-26455 published?

CVE-2023-26455 was published on 2023-11-02 and last updated on 2026-06-17.

CVE-2023-26455

CVE-2023-26455 is a medium-severity vulnerability in Open-xchange Open-xchange Appsuite with a CVSS 3.x base score of 5.6. 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-287.

Key facts

Severity: Medium (CVSS 3.x base score 5.6)
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Open-xchange Open-xchange Appsuite
Published: 2023-11-02
Last modified: 2026-06-17

Description

RMI was not requiring authentication when calling ChronosRMIService:setEventOrganizer. Attackers with local or adjacent network access could abuse the RMI service to modify calendar items using RMI. RMI access is restricted to localhost by default. The interface has been updated to require authenticated requests. No publicly available exploits are known.

Frequently asked questions

What is CVE-2023-26455?: RMI was not requiring authentication when calling ChronosRMIService:setEventOrganizer. Attackers with local or adjacent network access could abuse the RMI service to modify calendar items using RMI. RMI access is restricted to localhost by default. The interface has been updated to require authenticated requests. No publicly available exploits are known.
How severe is CVE-2023-26455?: CVE-2023-26455 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability low.
Is CVE-2023-26455 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-26455?: CVE-2023-26455 primarily affects Open-xchange Open-xchange Appsuite. In total, 43 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-26455?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-26455 published?: CVE-2023-26455 was published on 2023-11-02 and last updated on 2026-06-17.

References

Affected products (43)

cpe:2.3:a:open-xchange:open-xchange_appsuite:*:*:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:-:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6069:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6073:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6080:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6085:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6093:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6102:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6112:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6121:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6133:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6138:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6141:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6146:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6147:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6148:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6150:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6156:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6161:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6166:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6173:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6176:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6178:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6189:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6194:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6199:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6204:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6205:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6209:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6210:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6214:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6215:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6216:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6218:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6219:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6220:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6227:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6230:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6233:*:*:*:*:*:*
cpe:2.3:a:open-xchange:open-xchange_appsuite:7.10.6:patch_release_6235:*:*:*:*:*:*

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