Vulnary
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Critical· 9.2official fix available

CVE-2026-58155

Apache Traffic Server can truncate very long header names, which lets attackers create duplicate headers, smuggle requests, and bypass security policies. This flaw exists in versions 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, and 10.0.0 through 10.1.3. Upgrading to 9.2.15 or 10.1.4 removes the vulnerability.

publishedJul 29, 2026
last modifiedJul 29, 2026
sourcesNVD
severity · cvss
9.2
critical · how bad it is
exploitation · epss
<1%
18th percentile · chance of exploitation in 30 days
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →
auto-deletes from the system
counting…on Aug 28, 2026

An official fix is available, so this entry is kept for 30 days and then removed automatically.

01

Who is affected

Apache Traffic Server versions 8.0.0–8.1.9, 9.0.0–9.2.14, and 10.0.0–10.1.3.

02

Real-world impact

An attacker could use header aliasing and request smuggling to bypass security controls, potentially gaining unauthorized access or executing malicious actions.

03

Why this severity

The CVSS score of 9.2 reflects the high impact of the vulnerability: it allows attackers to bypass security policies and smuggle requests without authentication or user interaction, making it a critical flaw.

04

What to do about it

official fix available
recommended steps
  1. 01Upgrade Apache Traffic Server to version 9.2.15 or later, or to 10.1.4 or later.
  2. 02Restart the Traffic Server service to apply the update.

NVD-referenced vendor advisory

05

Timeline

  1. Jul 29, 2026 · 1d ago
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Jul 29, 2026 · 1d ago
    Official fix available
    A vendor patch or mitigation now exists — see the remediation steps above.
06

How it’s attacked

Attack vectorNetwork (remote)
Attack complexityLow
Attack requirementsNone
Privileges requiredNone
User interactionNone needed
Confidentiality impactNone
Integrity impactHigh
Availability impactNone
07

References & advisories

(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →