CVE-2026-40514: SmarterTools SmarterMail builds prior to 9610 contain a cryptographic weakness in the file and email sharing e

Q: How do I fix CVE-2026-40514?

smartermail: upgrade to 100.0.9610. Exact commands for each OS are on this page.

Q: Is CVE-2026-40514 being exploited?

CVE-2026-40514 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-40514 affect?

CVE-2026-40514 affects smartermail. Severity is medium (CVSS 5.9). 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 entr

Q: How urgent is CVE-2026-40514?

Priority 27/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.9REMOTEUPGRADE

CVE-2026-40514 is a medium-severity flaw (CVSS 5.9) affecting smartermail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 an

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 95%)
CISA exploited list	No
Weakness	CWE-338
Published	2026-04-27
Last modified	2026-10-26

Publisher (CNA): VulnCheck · Vendor: smartertools

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-27 15:16 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

smartertools smartermail UPGRADE

Affected: < 100.0.9610

Fixed in: 100.0.9610

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy smartermail || rpm -q smartermail || smartermail --version

2. UPGRADE to 100.0.9610 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade smartermail

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade smartermail

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40514?

smartermail: upgrade to 100.0.9610. Exact commands for each OS are on this page.

Is CVE-2026-40514 being exploited?

CVE-2026-40514 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40514 affect?

CVE-2026-40514 affects smartermail. Severity is medium (CVSS 5.9). 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 entr

How urgent is CVE-2026-40514?

Priority 27/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-7807 HIGH 8.1 UPGRADE SmarterTools SmarterMail builds prior to 9560 contain a local file inclusion vulnerability in the /api/v1/repo

References

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