How severe is CVE-2023-45648?

CVE-2023-45648 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-45648?

CVE-2023-45648 affects the following packages: org.apache.tomcat:tomcat (Maven), org.apache.tomcat:tomcat (Maven), org.apache.tomcat:tomcat (Maven), org.apache.tomcat:tomcat (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven), and 4 more. Ecosystems affected: Maven.

How do I fix CVE-2023-45648?

Update org.apache.tomcat:tomcat to 11.0.0-M12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-45648 is resolved across your whole dependency graph.

How do I detect CVE-2023-45648 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-45648 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2023-45648 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-45648 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-45648?

CVE-2023-45648 has an EPSS (Exploit Prediction Scoring System) score of 5.9%, placing it in the 93th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-45648?

CVE-2023-45648 is classified as Improper Input Validation (CWE-20). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for CVE-2023-45648?

A Nuclei detection template exists for CVE-2023-45648, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2023-45648 published, and has it been updated?

CVE-2023-45648 was published on October 10, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2023-45648 — tomcat

MEDIUMFix: apache/tomcat@5958324

CVE-2023-45648 is a medium-severity (CVSS 5.3) Improper Input Validation vulnerability in org.apache.tomcat:tomcat. A fix is available for org.apache.tomcat:tomcat — see the affected versions and patch details below.

Apache Tomcat: Trailer header parsing too lenient

Also known asBIT-tomcat-2023-45648GHSA-r6j3-px5g-cq3x

Published

Oct 10, 2023

Updated

Oct 28, 2026

Affected

12 pkgs

Patched

12 / 12

Exploits

None indexed

Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-45648.

EPSS Exploitation Probability

via FIRST.org ↗

5.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs93th percentile — riskier than 93% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

12 pkgs affected

☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core+4 more

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

12 total 12 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.tomcat:tomcat`	≥ 11.0.0-M1&&< 11.0.0-M12	11.0.0-M12`org.apache.tomcat:tomcat:11.0.0-M12`
☕Maven	`org.apache.tomcat:tomcat`	≥ 10.1.0-M1&&< 10.1.14	10.1.14`org.apache.tomcat:tomcat:10.1.14`
☕Maven	`org.apache.tomcat:tomcat`	≥ 9.0.0-M1&&< 9.0.81	9.0.81`org.apache.tomcat:tomcat:9.0.81`
☕Maven	`org.apache.tomcat:tomcat`	≥ 8.5.0&&< 8.5.94	8.5.94`org.apache.tomcat:tomcat:8.5.94`
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 11.0.0-M1&&< 11.0.0-M12	11.0.0-M12`org.apache.tomcat.embed:tomcat-embed-core:11.0.0-M12`
☕Maven	`org.apache.tomcat.embed:tomcat-embed-core`	≥ 10.1.0-M1&&< 10.1.14	10.1.14`org.apache.tomcat.embed:tomcat-embed-core:10.1.14`

Affected Products

2 products · 64 configurations

Application

tomcatapache

≥ 10.1.1 && < 10.1.14

3 versions

9.0.010.1.011.0.0

debian linuxdebian

3 versions

10.011.012.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat to 11.0.0-M12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-45648 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How to detect CVE-2023-45648

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id cve-2023-45648 -u https://target

Template: Apache Tomcat - HTTP Request Smuggling
Severity: medium
Impact: Attackers can perform request smuggling, potentially leading to cache poisoning, session hijacking, or bypassing security controls.
Remediation: Upgrade to version 11.0.0-M12, 10.1.14, 9.0.81, or 8.5.94 or later.

Template by ProjectDiscovery nuclei-templates (0x_Akoko), MIT licensed. View the full template. Scan only systems you are authorised to test.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

The request smuggling is not guaranteed to have relevant information within every request and the scenario behind a reverse proxy which fails to handle the request too is necessary, hence the Moderate impact. The Red Hat AMQ Broker team removed any tomcat dependencies in version 7.11.3. Please refer to…

Workaround published by Red Hat

No mitigation is currently available for this flaw.

Source: Red Hat security advisory for CVE-2023-45648 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat Enterprise Linux 10	`tomcat-1:10.1.36-1.el10_0`	RHSA-2025:7497
Red Hat Enterprise Linux 8	`tomcat-1:9.0.62-27.el8_9.2`	RHSA-2024:0125
Red Hat Enterprise Linux 8.8 Extended Update Support	`tomcat-1:9.0.87-1.el8_8.2`	RHSA-2024:3814
Red Hat Enterprise Linux 9	`tomcat-1:9.0.62-37.el9_3.1`	RHSA-2024:0474
Red Hat Fuse 7.12.1	`tomcat`	RHSA-2023:7247
Red Hat JBoss Web Server 5	`tomcat`	RHSA-2023:6207
Red Hat JBoss Web Server 5.7 on RHEL 7	`jws5-tomcat-0:9.0.62-18.redhat_00016.1.el7jws`	RHSA-2023:6206
Red Hat OpenShift Dev Spaces 3 Containers	`devspaces/server-rhel8:3.15-3`	RHSA-2024:4631

Frequently Asked Questions

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 is

O3 Security · Impact-Aware SCA

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