eastbaycyber

CVE-2026-44327: Unsafe Redirect Handling in Apache Traffic Server

CVE explainers 2 min read
SR
Security Research Desk Expert reviewed
Threat intelligence · Human-verified · Updated 2026-05-27
▲ Escalation ViewOne CVE, briefed at three altitudes — skim the Brief, weigh the Impact, or work the Runbook. The way a SOC actually reads it.
CISOBrief · 30-second brief

CVE-2026-44327 is a CWE-601 open redirect issue in Apache Traffic Server. This high-severity flaw affects versions before 9.2.11 and 10.0.0 through 10.0.5, allowing unsafe external redirects via a remap plugin parameter. It poses risks of phishing and cache poisoning. Administrators are urged to upgrade to the fixed versions 9.2.11 or 10.0.6 immediately.

What This Vulnerability Means in Practice

The vulnerability allows attackers to influence redirect behavior, leading to potentially serious consequences. When Apache Traffic Server is misconfigured, it can redirect users to malicious sites, increasing the risk of phishing attacks. Additionally, cache poisoning could mislead users by serving them incorrect content.

AnalystImpact · assess the risk

Affected Versions and Fixed Versions

The following versions are affected:

  • Apache Traffic Server before 9.2.11
  • Apache Traffic Server 10.0.0 through 10.0.5

To mitigate this vulnerability, upgrade to:

  • Apache Traffic Server 9.2.11
  • Apache Traffic Server 10.0.6

If you are unsure of your version, run the following command:

traffic_server -V

Exploitation Status and Defender Assumptions

As of now, there is no public confirmation of in-the-wild exploitation for CVE-2026-44327. However, the absence of evidence does not guarantee safety. Administrators should prioritize patching this vulnerability, especially if their Traffic Server is exposed to the internet.

Technical Deep Dive

The root cause of this vulnerability lies in the remap plugin parameter that can be exploited to perform unsafe redirects. The patch for this vulnerability emphasizes strict validation and allow-listing of redirect targets, which is essential to prevent potential exploitation.

ResponderRunbook · act now

How to Detect Exposure and Possible Abuse

To detect potential abuse, review your remap.config for any configurations that allow external redirects. Look for suspicious 3xx responses in your logs where the Location header points to unapproved external domains.

Mitigation and Patching Guidance

The primary mitigation is to upgrade to a fixed release. If immediate upgrades are not feasible, consider temporary measures such as avoiding the use of the affected remap plugin parameter. Implement strict allow-listing for redirect targets and monitor for unusual redirect traffic patterns.

References

For more information on related vulnerabilities, check out our articles on the best email encryption services for business and how to detect stored XSS in admin panels.

This article may contain affiliate links. We earn a commission on qualifying purchases at no extra cost to you.

Last verified: 2026-05-27

Disclaimer: This article may contain affiliate links. We earn a commission on qualifying purchases at no extra cost to you.