by Kastro
Paper/Archive/CVE-2026-40514

CVE-2026-40514

SmarterTools Inc. SmarterMail — SmarterTools SmarterMail < Build 9610 Cryptographic Weakness via Weak RNG

EPSS 0.2%CVSS 9.1
critical.is priorityof 100
28
CVSS 9.1 (NVD)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 4.6.046 × 200.9No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
SmarterMail< 100.0.9610100.0.9610CNA

Scores by source

NVD9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
VulnCheck (CNA)8.2CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
VulnCheck (CNA)5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: partial

References

patchsmartertools.com/smartermail/release-notes/currentwriteupvulncheck.com/advisories/smartertools-smartermail-build-9610-cryptographic-weakness-via-weak-rng