CVE-2023-26430

Name: CVE-2023-26430
Creator: NVD / NIST
Published: 2023-08-02T13:15:10.217+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.63%

Last modified Jun 17, 2026

CVE-2023-26430 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. Attackers with access to user accounts can inject arbitrary control characters to SIEVE mail-filter rules. This could be abused to access SIEVE extension that are not allowed by App Suite or to inject rules which would break per-user filter processing, requiring manual cleanup of such rules. EPSS estimates a 0.63% chance of exploitation in the next 30 days.

Description

Attackers with access to user accounts can inject arbitrary control characters to SIEVE mail-filter rules. This could be abused to access SIEVE extension that are not allowed by App Suite or to inject rules which would break per-user filter processing, requiring manual cleanup of such rules. We have added sanitization to all mail-filter APIs to avoid forwardning control characters to subsystems. No publicly available exploits are known.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

0.63%

45.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Open-Xchange	Open-Xchange Appsuite Backend	7.10.6
Open-Xchange	Open-Xchange Appsuite Backend	8.10.0

References

http://packetstormsecurity.com/files/173943/OX-App-Suite-SSRF-SQL-Injection-Cross-Site-Scripting.htmlThird Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2023/Aug/8Mailing List, Third Party Advisory
https://documentation.open-xchange.com/appsuite/security/advisories/csaf/2023/oxas-adv-2023-0003.json
https://software.open-xchange.com/products/appsuite/doc/Release_Notes_for_Patch_Release_6230_7.10.6_2023-05-02.pdfRelease Notes
http://packetstormsecurity.com/files/173943/OX-App-Suite-SSRF-SQL-Injection-Cross-Site-Scripting.htmlThird Party Advisory, VDB Entry
http://seclists.org/fulldisclosure/2023/Aug/8Mailing List, Third Party Advisory
https://documentation.open-xchange.com/appsuite/security/advisories/csaf/2023/oxas-adv-2023-0003.json
https://software.open-xchange.com/products/appsuite/doc/Release_Notes_for_Patch_Release_6230_7.10.6_2023-05-02.pdfRelease Notes

Timeline

Published: Aug 2, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-26430?

How severe is CVE-2023-26430?

CVE-2023-26430 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.63% probability of exploitation in the next 30 days.

How do I fix CVE-2023-26430?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-26430?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST