CVE-2026-40514
SmarterTools SmarterMail < Build 9610 Cryptographic Weakness via Weak RNG
Description
SmarterTools SmarterMail builds prior to 9610 contain a cryptographic weakness in the file and email sharing endpoints that use DES-CBC encryption with keys and initialization vectors derived from System.Random seeded with insufficient entropy, reducing the seed space to approximately 19,000 possible values. An unauthenticated attacker can use the attachment download endpoint as an oracle to determine the seed in use and derive encryption keys and initialization vectors to forge sharing tokens for arbitrary emails, attachments, or file storage contents without prior access to the targeted content.
INFO
Published Date :
April 27, 2026, 3:16 p.m.
Last Modified :
June 17, 2026, 10:45 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update SmarterMail to version 9610 or later.
- Ensure proper seeding of random number generators.
- Review and strengthen encryption key derivation.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40514.
| URL | Resource |
|---|---|
| https://www.smartertools.com/smartermail/release-notes/current | Release Notes |
| https://www.vulncheck.com/advisories/smartertools-smartermail-build-9610-cryptographic-weakness-via-weak-rng | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40514 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40514
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40514 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40514 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 04, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:smartertools:smartermail:*:*:*:*:*:*:*:* versions up to (excluding) 100.0.9610 Added Reference Type VulnCheck: https://www.smartertools.com/smartermail/release-notes/current Types: Release Notes Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/smartertools-smartermail-build-9610-cryptographic-weakness-via-weak-rng Types: Third Party Advisory -
New CVE Received by [email protected]
Apr. 27, 2026
Action Type Old Value New Value Added Description SmarterTools SmarterMail builds prior to 9610 contain a cryptographic weakness in the file and email sharing endpoints that use DES-CBC encryption with keys and initialization vectors derived from System.Random seeded with insufficient entropy, reducing the seed space to approximately 19,000 possible values. An unauthenticated attacker can use the attachment download endpoint as an oracle to determine the seed in use and derive encryption keys and initialization vectors to forge sharing tokens for arbitrary emails, attachments, or file storage contents without prior access to the targeted content. Added CVSS V4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-338 Added Reference https://www.smartertools.com/smartermail/release-notes/current Added Reference https://www.vulncheck.com/advisories/smartertools-smartermail-build-9610-cryptographic-weakness-via-weak-rng