CVE-2023-51765

Exploitation

Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.

SSVC decision

Not assessed by CISA

EPSS probability

1.08% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 64.9% of scored records. A rank, not a probability.

NVD base score

5.3 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2023-12-24 00:00Z2 YR AGO

Last updated

2024-08-02 22:48Z2 YR AGO

Reserved

2023-12-24

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-345Insufficient Verification of Data AuthenticityClass
• CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')Base

Data version

5.1

Document digest

9989d503ab53afae2b05c2c1bc3e2b76cb2916fc60e4818e9590bf0e0350567a

• sec-consult.comhttps://sec-consult.com/blog/detail/smtp-smuggling-spoofing-e-mails-worldwide/
• www.openwall.comhttps://www.openwall.com/lists/oss-security/2023/12/22/7
• www.openwall.comhttps://www.openwall.com/lists/oss-security/2023/12/21/7
• github.comhttps://github.com/freebsd/freebsd-src/commit/5dd76dd0cc19450133aa379ce0ce4a68ae07fb39#diff-afdf514b32ac88004952c11660c57bc96c3d8b2234007c1cbd8d7ed7fd7935cc
• www.openwall.com[oss-security] 20231224 Re: Re: New SMTP smuggling attackhttp://www.openwall.com/lists/oss-security/2023/12/24/1mailing-list
• www.openwall.com[oss-security] 20231225 Re: Re: New SMTP smuggling attackhttp://www.openwall.com/lists/oss-security/2023/12/25/1mailing-list
• bugzilla.suse.comhttps://bugzilla.suse.com/show_bug.cgi?id=1218351
• bugzilla.redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=2255869
• access.redhat.comhttps://access.redhat.com/security/cve/CVE-2023-51765
• fahrplan.events.ccc.dehttps://fahrplan.events.ccc.de/congress/2023/fahrplan/events/11782.html
• www.openwall.com[oss-security] 20231226 Re: New SMTP smuggling attackhttp://www.openwall.com/lists/oss-security/2023/12/26/5mailing-list
• www.openwall.com[oss-security] 20231229 Re: Re: New SMTP smuggling attackhttp://www.openwall.com/lists/oss-security/2023/12/29/5mailing-list
• www.openwall.com[oss-security] 20231230 Re: Re: New SMTP smuggling attackhttp://www.openwall.com/lists/oss-security/2023/12/30/3mailing-list
• www.openwall.com[oss-security] 20231230 Re: Re: New SMTP smuggling attackhttp://www.openwall.com/lists/oss-security/2023/12/30/1mailing-list
• www.youtube.comhttps://www.youtube.com/watch?v=V8KPV96g1To
• lwn.nethttps://lwn.net/Articles/956533/
• lists.debian.org[debian-lts-announce] 20240615 [SECURITY] [DLA 3829-1] sendmail security updatehttps://lists.debian.org/debian-lts-announce/2024/06/msg00004.htmlmailing-list