High severity · published Jul 18, 2026
CVE-2026-59173
Apache Traffic Server: DoS vulnerability in HTTP/2 via stalled flow-control conditions
7.5
CVSS
0.7%
EPSS
No
On KEV
Description
Uncontrolled Resource Consumption vulnerability in Apache Traffic Server.
This issue affects Apache Traffic Server: from 9.0.0 through 9.1.13, from 10.0.0 through 10.1.2.
Users are recommended to upgrade to version 9.1.14 or 10.1.3, which fixes the issue.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 54% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AT
Apache Traffic Server · Apache Software Foundation
9.0.0 through 9.2.13; 10.0.0 through 10.1.2 · source: vendor
TS
Traffic Server · Apache
9.0.0 before 9.2.14; 10.0.0 before 10.1.3 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59173
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-59173
Mailing List
https://lists.apache.org/thread/lhlbhphmv5dsfgx1fx84mgonzbocpzhd
Mailing List
http://www.openwall.com/lists/oss-security/2026/07/17/5
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