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Apache Traffic Server CVE-2026-58158

| EUVDEUVD-2026-50211 HIGH
Stack-based Buffer Overflow (CWE-121)
2026-07-29 apache GHSA-99g5-7fmc-568c
8.2
CVSS 4.0 · Vendor: apache
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Severity by source

Vendor (apache) PRIMARY
8.2 MEDIUM
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/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:X
vuln.today AI
5.9 MEDIUM

Network-reachable and unauthenticated, but AC:H because the non-default PROXY-protocol feature must be enabled; impact is availability-only (crash), so C:N/I:N/A:H.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (apache).

CVSS VectorVendor: apache

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/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:X
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
X

Lifecycle Timeline

7
Analysis Updated
Jul 29, 2026 - 10:52 vuln.today
v3 (cvss_changed)
Analysis Updated
Jul 29, 2026 - 10:52 vuln.today
v2 (cvss_changed)
Re-analysis Queued
Jul 29, 2026 - 10:22 vuln.today
cvss_changed
Severity Changed
Jul 29, 2026 - 10:22 NVD
MEDIUM HIGH
CVSS changed
Jul 29, 2026 - 10:22 NVD
5.9 (MEDIUM) 8.2 (HIGH)
Analysis Generated
Jul 29, 2026 - 10:00 vuln.today
CVE Published
Jul 29, 2026 - 08:26 cve.org
MEDIUM 5.9

DescriptionCVE.org

Apache Traffic Server mishandles PROXY protocol input, truncating ports and overflowing the stack.

This issue affects Apache Traffic Server: from 8.0.0 through 8.1.9, from 9.0.0 through 9.2.14, from 10.0.0 through 10.1.3.

Users are recommended to upgrade to version 9.2.15 or 10.1.4, which fix the issue.

AnalysisAI

Denial-of-service (and potential memory-corruption) in Apache Traffic Server arises from mishandling of PROXY protocol input, where malformed port fields are truncated and cause a stack buffer overflow (CWE-121). Affected releases span the 8.x, 9.x, and 10.x branches (8.0.0-8.1.9, 9.0.0-9.2.14, 10.0.0-10.1.3), and remote attackers can crash the proxy when it is configured to accept PROXY protocol connections. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
Reach ATS PROXY-protocol listener
Delivery
Open TCP connection
Exploit
Send crafted PROXY header with malformed port
Execution
Truncated port overflows stack buffer
Impact
Crash proxy process / deny service

Vulnerability AssessmentAI

Exploitation The affected ATS listener must be configured to accept the PROXY protocol on inbound connections (the AT:P Attack Requirement in the CVSS vector) - this is not a default configuration, so instances that never enable PROXY protocol acceptance are not exposed. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The CVSS 4.0 vector (AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H) tells a nuanced story: exploitation is network-reachable, low-complexity, and unauthenticated, but carries an Attack Requirement (AT:P) - the PROXY protocol feature must be enabled, which is not the default. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario An attacker who can reach an ATS listener that is configured to accept the PROXY protocol opens a TCP connection and sends a crafted PROXY header with a malformed/oversized port field. ATS truncates the port and overflows a fixed stack buffer while parsing, crashing the proxy process and denying service to legitimate traffic; because the overflow is on the stack, escalation beyond DoS cannot be excluded. …
Remediation Vendor-released patch: upgrade to Apache Traffic Server 9.2.15 (for the 8.x and 9.x branches) or 10.1.4 (for the 10.x branch) per the Apache advisory at https://lists.apache.org/thread/5prl9glcm9g2swnq9hqxvnokylm1gr6d; 8.x is EOL and has no in-branch fix, so 8.x operators should move to 9.2.15 or later. … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 24 hours: Audit all Apache Traffic Server deployments to identify instances running versions 8.0.0-8.1.9, 9.0.0-9.2.14, or 10.0.0-10.1.3 and verify whether PROXY protocol is enabled; disable PROXY protocol immediately if operationally feasible. …

Sign in for detailed remediation steps and compensating controls.

Threat intelligence, references, and detailed analysis are available after sign-in.

CVE-2026-58161 CRITICAL
9.2 Jul 29

Remote denial of service in Apache Traffic Server (8.0.0-8.1.9, 9.0.0-9.2.14, 10.0.0-10.1.3) allows unauthenticated atta

CVE-2026-58154 CRITICAL
9.2 Jul 29

Out-of-bounds write and integer overflow in Apache Traffic Server's MIME and HTTP header parsing lets remote attackers c

CVE-2026-58155 CRITICAL
9.2 Jul 29

Request smuggling and policy bypass in Apache Traffic Server (branches 8.0.0-8.1.9, 9.0.0-9.2.14, and 10.0.0-10.1.3) ari

CVE-2026-58151 HIGH
8.7 Jul 29

Denial of service in Apache Traffic Server 8.0.0-8.1.9, 9.0.0-9.2.14, and 10.0.0-10.1.3 lets remote unauthenticated atta

CVE-2026-58188 HIGH
8.4 Jul 29

Out-of-bounds write and limit-bypass flaws in several experimental plugins shipped with Apache Traffic Server (8.0.0-8.1

CVE-2026-58162 HIGH
8.4 Jul 29

Improper certificate generation in the Apache Traffic Server certifier plugin lets remote attackers dictate the contents

CVE-2026-58164 HIGH
8.3 Jul 29

Memory corruption in Apache Traffic Server's remap configuration handling lets remote attackers trigger a use-after-free

CVE-2026-58163 HIGH
8.3 Jul 29

Denial-of-service and cache-integrity corruption in Apache Traffic Server (8.0.0-8.1.9, 9.0.0-9.2.14, 10.0.0-10.1.3) all

CVE-2026-58184 HIGH
8.3 Jul 29

Out-of-bounds memory write in the Apache Traffic Server header_rewrite plugin allows remote attackers to crash the proxy

CVE-2026-58177 HIGH
8.3 Jul 29

Memory corruption in the Cripts scripting framework of Apache Traffic Server (versions 10.0.0 through 10.1.3) allows rem

CVE-2026-58180 HIGH
8.2 Jul 29

Denial of service in Apache Traffic Server (versions 8.0.0-8.1.9, 9.0.0-9.2.14, and 10.0.0-10.1.3) arises from a stack-b

CVE-2026-58178 HIGH
8.2 Jul 29

Denial of service in the Apache Traffic Server ESI (Edge Side Includes) plugin allows remote unauthenticated attackers t

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CVE-2026-58158 vulnerability details – vuln.today

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