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NVD / CVE Program· CNA mitre

CVE-2016-9920: steps/mail/sendmail.inc in Roundcube before 1.1.7 and 1.2.x before 1.2.3, when no SMTP server is configured and the sendmail program is…

HighCVSS 7.5 · v3.0—Proof of concept Fix available

Noroxi assessment

Priority: Monitor (action score 32/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 5.6% (FIRST EPSS); higher than 93% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: roundcube (Debian:12) 1.2.3+dfsg.1-1; roundcube (Debian:7) 0.7.2-9+deb7u5.

Low priority for now. Upgrade to roundcube (Debian:12) 1.2.3+dfsg.1-1; roundcube (Debian:7) 0.7.2-9+deb7u5 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

steps/mail/sendmail.inc in Roundcube before 1.1.7 and 1.2.x before 1.2.3, when no SMTP server is configured and the sendmail program is enabled, does not properly restrict the use of custom envelope-from addresses on the sendmail command line, which allows remote authenticated users to execute arbitrary code via a modified HTTP request that sends a crafted e-mail message.

Published
Dec 8, 2016
Updated
Jun 16, 2026
EPSS
5.6% · 93th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
2 / 30 · 5.6%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2016-9920

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
roundcubewebmail

Using webmail? Add it to your stack and be the first to know about CVEs like this one. (Email server)

Watch new CVEs for webmail

When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or is weaponized

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • roundcube webmailup to 1.1.6 inclusive
  • roundcube webmail1.2.0
  • roundcube webmail1.2.1
  • roundcube webmail1.2.2

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12roundcubebefore 1.2.3+dfsg.1-11.2.3+dfsg.1-1
Debian:7roundcubebefore 0.7.2-9+deb7u50.7.2-9+deb7u5

Other highest-scoring records for the same primary product.

  • CVE-2025-49113Roundcube Webmail before 1.5.10 and 1.6.x before 1.6.11 allows remote code execution by authenticated users because the _from parameter in…KEV
    95Now
  • CVE-2020-12641rcube_image.php in Roundcube Webmail before 1.4.4 allows attackers to execute arbitrary code via shell metacharacters in a configuration…KEV
    94Now
  • CVE-2024-42009A Cross-Site Scripting vulnerability in Roundcube through 1.5.7 and 1.6.x through 1.6.7 allows a remote attacker to steal and send emails…KEV
    92Now

Published before and after this one in the same product

  • ← EarlierCVE-2015-8793Jan 29, 2016 · Cross-site scripting (XSS) vulnerability in program/include/rcmail.php in Roundcube before 1.0.6 and 1.1.x before 1.1.2 allows remote…
    24Monitor
  • ← EarlierCVE-2016-4069Aug 25, 2016 · Cross-site request forgery (CSRF) vulnerability in Roundcube Webmail before 1.1.5 allows remote attackers to hijack the authentication of…
    36Monitor
  • Later →CVE-2016-4552Dec 20, 2016 · Cross-site scripting (XSS) vulnerability in Roundcube Webmail before 1.2.0 allows remote attackers to inject arbitrary web script or HTML…
    24Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:roundcube1.2.3+dfsg.1-1 · Debian:12Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:482017-01-06

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+28 d
  3. TodayNov 15, 2026+3629 d

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

CVSS vector

CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records