CVE-2015-9097: The mail gem before 2.5.5 for Ruby (aka A Really Ruby Mail Library) is vulnerable to SMTP command injection vi

Q: How do I fix CVE-2015-9097?

mail: upgrade to newer than 2.5.4. Exact commands for each OS are on this page.

Q: Is CVE-2015-9097 being exploited?

CVE-2015-9097 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-2015-9097 affect?

CVE-2015-9097 affects mail. Severity is medium (CVSS 6.1). The mail gem before 2.5.5 for Ruby (aka A Really Ruby Mail Library) is vulnerable to SMTP command injection via CRLF sequences in a RCPT TO or MAIL FROM command, as demonstrated by CRLF sequences immediately before and after a DATA substrin

Q: How urgent is CVE-2015-9097?

Priority 49/100. Public exploit reference

This month

MEDIUM 6.1UPGRADE

CVE-2015-9097 is a medium-severity flaw (CVSS 6.1) affecting mail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The mail gem before 2.5.5 for Ruby (aka A Really Ruby Mail Library) is vulnerable to SMTP command injection via CRLF sequences in a RCPT TO or MAIL FROM command, as demonstrated by CRLF sequences immediately before and after a DATA substring.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	3.4% (top 11%)
CISA exploited list	No
Weakness	CWE-93
Published	2017-06-12
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: mail project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2017-06-12 20:29 UTCPublished CVE record published
2026-06-17 00:35 UTCUpdated Record last modified

mail project mail UPGRADE

Affected: <= 2.5.4

Fixed in: newer than 2.5.4

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.5.4 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mail

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-2015-9097?

mail: upgrade to newer than 2.5.4. Exact commands for each OS are on this page.

Is CVE-2015-9097 being exploited?

CVE-2015-9097 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-2015-9097 affect?

CVE-2015-9097 affects mail. Severity is medium (CVSS 6.1). The mail gem before 2.5.5 for Ruby (aka A Really Ruby Mail Library) is vulnerable to SMTP command injection via CRLF sequences in a RCPT TO or MAIL FROM command, as demonstrated by CRLF sequences immediately before and after a DATA substrin

How urgent is CVE-2015-9097?

Priority 49/100. Public exploit reference

Software pages

Ruby vulnerabilities

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References

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