CVE-2023-45648 | Apache Tomcat: Trailer header parsing too lenient

Improper Input Validation vulnerability in Apache Tomcat.Tomcat from 11.0.0-M1 through 11.0.0-M11, from 10.1.0-M1 through 10.1.13, from 9.0.0-M1 through 9.0.81 and from 8.5.0 through 8.5.93 did not correctly parse HTTP trailer headers. A specially crafted, invalid trailer header could cause Tomcat to treat a single request as multiple requests leading to the possibility of request smuggling when behind a reverse proxy. Older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.0-M12 onwards, 10.1.14 onwards, 9.0.81 onwards or 8.5.94 onwards, which fix the issue.

Published: 2023-10-10 Last update: 2025-08-07 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-45648 is rated Moderate Risk (48.5/100): CVSS Medium severity, with high exploitation likelihood (EPSS 5.85%, 92th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-45648

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 62.08% 5.85% -56.23%
2 2026-06-02 62.75% 62.08% -0.67%
3 2026-05-22 — 62.75% —

Full EPSS history (38 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-45648

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2023-45648

GitHub Security Advisory for CVE-2023-45648

GHSA-r6j3-px5g-cq3x · Severity: medium · Ecosystem: maven — Apache Tomcat Improper Input Validation vulnerability

OS Trackers for CVE-2023-45648

vendor priority summary link
debian not yet assigned CVE-2023-45648 not yet assigned priority: Debian including 2 source packages (tomcat10, tomcat9), 9 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 9. https://security-tracker.debian.org/tracker/CVE-2023-45648
redhat medium — https://access.redhat.com/security/cve/CVE-2023-45648
suse high CVE-2023-45648 severity important: SUSE including 97 source package names (5.0.0-beta1.2.122:tomcat-9.0.85-150200.57.1, 5.0.0-beta1.2.122:tomcat-el-3_0-api-9.0.85-150200.57.1, …), 313 product×package rows across 47 product lines (Container containers/apache-tomcat, Container suse/manager/5.0/x86_64/server, … (47 product lines)): Fixed 292, Known Not Affected 21. https://www.suse.com/security/cve/CVE-2023-45648/
ubuntu medium CVE-2023-45648 medium priority: Ubuntu including 6 source packages (tomcat10, tomcat11, tomcat6, tomcat7, tomcat8, tomcat9), 60 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 25, ignored 19, released 10, not-affected 4, needs-triage 2. https://ubuntu.com/security/CVE-2023-45648

Affected software / configurations for CVE-2023-45648

Vendor Product Version Raw CPE
apache tomcat >= 8.5.0, < 8.5.94 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat >= 9.0.1, < 9.0.81 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat >= 10.1.1, < 10.1.14 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone1:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone10:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone11:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone12:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone13:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone14:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone15:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone16:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone17:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone18:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone19:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone2:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone20:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone21:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone22:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone23:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone24:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone25:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone26:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone27:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone3:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone4:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone5:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone6:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone7:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone8:*:*:*:*:*:*
apache tomcat 9.0.0 cpe:2.3:a:apache:tomcat:9.0.0:milestone9:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone1:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone10:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone11:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone12:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone13:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone14:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone15:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone16:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone17:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone18:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone19:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone2:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone20:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone3:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone4:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone5:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone6:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone7:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone8:*:*:*:*:*:*
apache tomcat 10.1.0 cpe:2.3:a:apache:tomcat:10.1.0:milestone9:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone1:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone10:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone11:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone2:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone3:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone4:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone5:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone6:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone7:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone8:*:*:*:*:*:*
apache tomcat 11.0.0 cpe:2.3:a:apache:tomcat:11.0.0:milestone9:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
debian debian_linux 12.0 cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*

References for CVE-2023-45648

cvelogic Threat Intelligence