CVE-2023-46589

Apache Tomcat: HTTP request smuggling via malformed trailer headers

HIGH
7.5
CVSS Score
Published: November 28, 2023 at 03:31 PM UTC
Updated: June 17, 2026 at 06:31 AM UTC
1 product affected across 1 vendorTomcat

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Severity
HIGH7.5
Exploit prediction
EPSS 3%
SSVC
No known exploit

Description

Improper Input Validation vulnerability in Apache Tomcat.Tomcat from 11.0.0-M1 through 11.0.0-M10, from 10.1.0-M1 through 10.1.15, from 9.0.0-M1 through 9.0.82 and from 8.5.0 through 8.5.95 did not correctly parse HTTP trailer headers. A trailer header that exceeded the header size limit 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-M11 onwards, 10.1.16 onwards, 9.0.83 onwards or 8.5.96 onwards, which fix the issue.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

10.1.0 ≤ v < 10.1.1610.1.0-M1 ≤ v ≤ 10.1.1511.0.0-M1 ≤ v ≤ 11.0.0-M1011.0.0-m1 ≤ v ≤ 11.0.0-m108.5.0 ≤ v ≤ 8.5.958.5.0 ≤ v < 8.5.969.0.0 ≤ v < 9.0.839.0.0-M1 ≤ v ≤ 9.0.8210.1.0-M111.0.0 milestone111.0.0 milestone1011.0.0 milestone211.0.0 milestone311.0.0 milestone411.0.0 milestone511.0.0 milestone611.0.0 milestone711.0.0 milestone811.0.0 milestone911.0.0-M111.0.0-m18.5.09.0.0-M1
Affected range stops below 10.1.16, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.5.96, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.0.83, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 10.0.0-M1 (unknown)
Vendor states this is fixed in 3 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-444

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