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NVD / CVE Program· CNA redhat

CVE-2026-93573: Io.netty/netty-codec-http: netty split transfer-encoding fields bypass final-chunked validation and enable request smuggling

Noroxi assessment

Priority: Monitor (action score 26/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.89% (FIRST EPSS); higher than 59.2% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A flaw was found in Netty's HTTP/1.1 decoder. This vulnerability allows a remote attacker to bypass `Transfer-Encoding` header validation by splitting the `Transfer-Encoding` field across multiple headers, with the last field containing a non-final transfer coding like `gzip` or `deflate`. This bypass can lead to HTTP request smuggling, enabling attackers to bypass security controls, desynchronize request processing, or cause requests to be processed in an unintended context.

MediumCVSS 6.5 · v3.1—No exploit No fix recorded
Published
Sep 18, 2026
Updated
Oct 15, 2026
EPSS
0.8% · 59th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.8%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · redhat
6.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-93573

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • Red Hat Red Hat AMQ Broker 7

    • all versionsaffected

  • Red Hat Red Hat AMQ Clients

    • all versionsaffected

  • Red Hat Red Hat build of Apache Camel 4 for Quarkus 3

    • all versionsaffected

  • Red Hat Red Hat build of Apache Camel for Spring Boot 4

    • all versionsaffected

  • Red Hat Red Hat build of Apicurio Registry 3

    • all versionsaffected

  • Red Hat Red Hat Build of Debezium 3.6

    • all versionsunknown

  • Red Hat Red Hat Build of Keycloak

    • all versionsaffected

  • Red Hat Red Hat build of Quarkus 3.27.5.SP2

    • all versionsunknown

  • Red Hat Red Hat build of Quarkus 3.33.3.SP2

    • all versionsunknown

  • Red Hat Red Hat Data Grid 8

    • all versionsaffected

  • Red Hat Red Hat Fuse 7

    • all versionsunknown

  • Red Hat Red Hat JBoss Enterprise Application Platform 7

    • all versionsunknown

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12nettyfrom 0—

Same product

red hat: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-93569Io.netty/netty-codec-http2: http/1 absolute-form host mismatch is translated to http/2 :authority, overriding the request-target authority
    33Monitor
  • CVE-2026-101292Artemis-core-client: unsafe reflection in apache activemq artemis federation message deserialization
    32Monitor
  • CVE-2026-84218Org.jolokia/jolokia-core: incomplete jndi denylist in jolokia jsr-160 proxy (bypass of cve-2018-1000130 fix)
    32Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-93567Sep 18, 2026 · Io.netty/netty-codec-http2: http/1 authority-form connect is translated to malformed http/2 connect with host-controlled :authority
    31Monitor
  • ← EarlierCVE-2026-93568Sep 18, 2026 · Io.netty/netty-codec-http2: io.netty/netty-codec-http3: netty: http/2 and http/3 extended connect requests are downgraded as regular connect requests
    30Monitor
  • Later →CVE-2026-93579Sep 18, 2026 · Io.netty/netty-codec-http2: netty: http/2 header field values are not validated by default (cr/lf/nul passthrough)
    26Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days+1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-935690 days apartIo.netty/netty-codec-http2: http/1 absolute-form host mismatch is translated to http/2 :authority, overriding the request-target authority
    33Monitor
  • CVE-2026-935740 days apartIo.netty/netty-codec-http: netty: http request smuggling via post-digit whitespace in chunk-size parsing
    26Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records