Header Truncation Vulnerability in Apache Traffic Server Affects Multiple Versions
CVE-2026-58155

9.2CRITICAL

Key Information:

Vendor

Apache
Status
Apache Traffic Server
Vendor
CVE Published:
29 July 2026

What is CVE-2026-58155?

A vulnerability in Apache Traffic Server arises from the improper truncation of over-long header names, which can lead to header aliasing, request smuggling, and policy bypass. Versions 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, and 10.0.0 through 10.1.3 are impacted. Users should promptly upgrade to version 9.2.15 or 10.1.4 to mitigate these risks.

Affected Version(s)

Apache Traffic Server 8.0.0 <= 8.1.9

Apache Traffic Server 9.0.0 <= 9.2.14

Apache Traffic Server 10.0.0 <= 10.1.3

References

https://lists.apache.org/thread/5prl9glcm9g2swnq9hqxvnoky...
vendor-advisory

CVSS V4

Score:
9.2
Severity:
CRITICAL
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Omkhar Arasaratnam
.