CVE-2023-51747
SMTP smuggling in Apache James
Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling.
A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks.
The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction.
We recommend James users to upgrade to non vulnerable versions.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
7.1
SMTP smuggling in Apache James
Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling.
A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks.
The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction.
We recommend James users to upgrade to non vulnerable versions.
- Record
CVE-2023-51747- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N - Weakness
- CWE-20, CWE-444, CWE-290
- Updated
- 2026-11-02
EUVDEUVD-2024-0681
7.1
Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling.
A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks.
The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction.
We recommend James users to upgrade to non vulnerable versions.
- Record
EUVD-2024-0681- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-p5q9-86w4-2xr5
7.1
SMTP smuggling in Apache James
Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling.
A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks.
The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction.
We recommend James users to upgrade to non vulnerable versions.
- Record
GHSA-p5q9-86w4-2xr5- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N - Weakness
- CWE-20, CWE-290
- Updated
- 2026-11-02
NVD
7.1
Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling.
A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks.
The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction.
We recommend James users to upgrade to non vulnerable versions.
- Record
CVE-2023-51747- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N - Weakness
- CWE-20, CWE-290, CWE-444
- Updated
- 2026-11-02
OSV
7.1
SMTP smuggling in Apache James
Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling.
A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks.
The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction.
We recommend James users to upgrade to non vulnerable versions.
- Record
CVE-2023-51747- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSVGHSA-p5q9-86w4-2xr5
7.1
SMTP smuggling in Apache James
Apache James prior to versions 3.8.1 and 3.7.5 is vulnerable to SMTP smuggling.
A lenient behaviour in line delimiter handling might create a difference of interpretation between the sender and the receiver which can be exploited by an attacker to forge an SMTP envelop, allowing for instance to bypass SPF checks.
The patch implies enforcement of CRLF as a line delimiter as part of the DATA transaction.
We recommend James users to upgrade to non vulnerable versions.
- Record
GHSA-p5q9-86w4-2xr5- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N - Weakness
- CWE-20, CWE-290
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
org.apache.james:james-serverMaven |
before 3.7.5 | 3.7.5 |
org.apache.james:james-serverMaven |
3.8.0 to 3.8.0 | 3.8.1 |
org.apache.james:james-serverMaven |
before 3.7.5, plus listed versions 3.0-M13.0-M23.0-beta23.0-beta33.0-beta4 Show 16 moreShow less3.0.03.0.0-RC13.0.0-beta53.0.13.1.03.2.03.3.03.4.03.5.03.6.03.6.23.7.03.7.13.7.23.7.33.7.4 |
3.7.5 |
org.apache.james:james-serverMaven |
3.8.0 up to 3.8.1 | 3.8.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-51747 is a high vulnerability (CVSS 7.1) in Apache James, published February 27, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.04%, the 64th percentile. Fixed in org.apache.james:james-server 3.7.5.
References
sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide
postfix.org/smtp-smuggling.html
lists.apache.org/thread/rxkwbkh9vgbl9rzx1fkllyk3krhgydko
openwall.com/lists/oss-security/2024/02/27/4
nvd.nist.gov/vuln/detail/CVE-2023-51747
github.com/apache/james-project/commit/d1ef102540e504c067b6c1721a6f1e7eee9c6fc6