CVE-2024-23655Public exploitNetwork attack vector

Mailbox denial of service via mismatched encryption key

Published Jan 25, 2024 · Updated Nov 13, 2024

Improper input validation in Tutao GmbH Tuta Mail 3.118.12 through 3.119.9 allows remote attackers to block mailbox access. Message processing attempts to decrypt ciphertext encrypted to a different recipient key, and the error path leaves WebSocket updates and mail loading stuck. Exploitation requires a manipulated Tuta-to-Tuta encrypted message; affected users lose inbox access and some mail and settings operations.

CVSS severity7.5
High
EPSS probability0.79%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Tutao GmbH Tuta Mail 3.118.12 through 3.119.9 allows remote attackers to block mailbox access. Message processing attempts to decrypt ciphertext encrypted to a different recipient key, and the error path leaves WebSocket updates and mail loading stuck. Exploitation requires a manipulated Tuta-to-Tuta encrypted message; affected users lose inbox access and some mail and settings operations.

The record

CVE
CVE-2024-23655
Published
Jan 25, 2024
Updated
Nov 13, 2024
Vendor
Tutao GmbH
Product
Tuta Mail
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 25, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 13, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 3.118.12, < 3.119.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Tutao GmbH · Tuta Mailversion=>= 3.118.12, < 3.119.10

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5GitHub CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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