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% (8th 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% (8th 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% (8th 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:*:*:*:*:*:*

More vulnerabilities in Open-xchange Open-xchange Appsuite

CVE-2017-13667 — Critical (CVSS 9.9): OX Software GmbH OX App Suite 7.8.4 and earlier is affected by: SSRF.
CVE-2020-12645 — Critical (CVSS 9.8): OX App Suite 7.10.1 to 7.10.3 has improper input validation for rate limits with a crafted User-Agent header, spoofed…
CVE-2019-7158 — Critical (CVSS 9.8): OX App Suite 7.10.0 and earlier has Incorrect Access Control.
CVE-2017-5212 — Critical (CVSS 9.8): Open-Xchange GmbH OX App Suite 7.8.3 is affected by: Incorrect Access Control.
CVE-2017-5210 — Critical (CVSS 9.8): Open-Xchange GmbH OX App Suite 7.8.3 and earlier is affected by: Information Exposure.
CVE-2017-17060 — Critical (CVSS 9.8): OX Software GmbH OX App Suite 7.8.4 and earlier is affected by: Insecure Permissions.

All CVEs affecting Open-xchange Open-xchange Appsuite →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

Browse all CWE-287 (Improper Authentication) vulnerabilities →