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CVE-2026-111809

Apache Traffic Server: HEAD requests carrying Content-Length or Transfer-Encoding enable request smuggling

CVSS score

9.3

EPSS probability

—

Risk score

0.9

Published

3 h ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Patch status has not yet been verified

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Vulnerability description

DayBreach AI Explanation

Verified against sources

Request Smuggling Vulnerability in Apache Traffic Server

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

The vulnerability CVE-2026-111809 found in Apache Traffic Server allows request smuggling via HEAD requests carrying Content-Length or Transfer-Encoding headers. Affected versions include 8.0.0 through 8.1.11, 9.0.0 through 9.2.15, 10.0.0 through 10.1.4, and 10.2.0.

Why does it matter?

This critical severity flaw can allow attackers to perform request smuggling, bypassing security controls and threatening data integrity.

What should be done?

  • Users are advised to check relevant vendor advisories
  • Follow vendor recommendations where applicable
Chain of evidence and sources3 verified claims

Apache Traffic Server, Content-Length veya Transfer-Encoding içeren HEAD istekleri üzerinden istek kaçakçılığına izin verir.

S0 · daybreach-canonicalS1 · cvelist

Zafiyet 8.0.0 ile 8.1.11, 9.0.0 ile 9.2.15, 10.0.0 ile 10.1.4 ve 10.2.0 sürümlerini etkilemektedir.

S0 · daybreach-canonicalS1 · cvelist

Söz konusu güvenlik açığı 9.3 CVSS taban puanına ve CRITICAL derecesine sahiptir.

S0 · daybreach-canonical
Show the technical text from the sources

Apache Traffic Server allows request smuggling via HEAD requests that carry Content-Length or Transfer-Encoding. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.

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

CWE: CWE-444

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-111809 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1Apache Software FoundationApache Traffic Server View
Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
9.3CVSS V31CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:NNVD
9.3CVSS V3_1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:NCVE CNA
6.9CVSS V40MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD
6.9CVSS V4_0MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:H/SA:NCVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-111809 is associated with the following CWEs:

CWE-444: Common Weakness Enumeration Entry CWE-444

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-111809 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kcvendor-advisory

CVSS Vector Radar Chart

9.3 / 10
Attack VectorNetworkComplexityLowPrivilegesNoneUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityNone

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)None

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

AS
Apache Software Foundation logo
Apache Software Foundation

Weakness Type (CWE & CAPEC)

CWE-444

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CVE-2026-111809 · Apache Traffic Server: HEAD requests…