CVE-2023-26432

What it is

When adding an external mail account, processing of SMTP "capabilities" responses are not limited to plausible sizes. Attacker with access to a rogue SMTP service could trigger requests that lead to excessive resource usage and eventually service unavailability. We now limit accepted SMTP server response to reasonable length/size. No publicly available exploits are known.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

1.1% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2023-06-20 08:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 05:43 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.1% in the next 30 days (EPSS).
• Severity: 4.3 MEDIUM (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2023-06-20 08:15 UTC

Last modified

2026-06-17 05:43 UTC

Exploit probability

1.1% · EPSS, next 30 days

Weakness

CWE-400 · Uncontrolled resource consumption

Record status

Modified

Affected

• open-xchange Appsuite Backend < 7.10.6
• open-xchange Appsuite Backend < 8.11.0
• open-xchange Appsuite Backend 7.10.6

Attack profile CVSS 3.1 · 4.3

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-26432.md and follow it. Check whether this project is affected by CVE-2023-26432. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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