Severity by source
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
Network-reachable with no auth (AV:N/PR:N) but requires the non-default txn_box plugin and specific oversized input (AC:H); impact is availability-only DoS (A:H, C:N/I:N).
Primary rating from Vendor (apache).
CVSS VectorVendor: apache
Lifecycle Timeline
6DescriptionCVE.org
The Apache Traffic Server txn_box plugin overflows the stack from attacker-controlled input.
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 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-based buffer overflow in the txn_box plugin, which copies attacker-controlled input onto the stack without adequate bounds checking. Remote attackers reaching an ATS instance that loads the txn_box transaction-manipulation plugin can crash the server process; the CVSS 4.0 vector (8.2) scores the impact as availability-only (VA:H) with no confidentiality or integrity loss. There is no public exploit identified at time of analysis and the issue is not listed in CISA KEV.
Technical ContextAI
Apache Traffic Server is a high-performance caching HTTP forward/reverse proxy widely used at CDN and edge scale. The flaw resides in txn_box, an experimental ATS plugin that lets operators rewrite and manipulate transactions (headers, URLs, request/response fields) via a declarative configuration. The root cause is CWE-121 (stack-based buffer overflow): the plugin writes attacker-influenced data into a fixed-size stack buffer without validating its length, corrupting adjacent stack memory such as saved registers or the return address. Because txn_box processes live request data, hostile input arrives over the network path the proxy already serves. The CPE cpe:2.3:a:apache_software_foundation:apache_traffic_server:*:*:*:*:*:*:*:* identifies the ATS package itself; the vulnerable code path is only reachable when the txn_box plugin is deployed and configured.
RemediationAI
Vendor-released patch: upgrade to Apache Traffic Server 9.2.15 or 10.1.4, which fix the overflow; the 8.x line is affected through 8.1.9 with no fixed 8.x release named in the advisory, so 8.x operators should migrate to a patched 9.2.x or 10.1.x build. If immediate upgrade is not possible, the most effective compensating control is to unload or disable the txn_box plugin in plugin.config/remap.config, since the vulnerable code path is only reachable when that experimental plugin is active - the trade-off is loss of any transaction-rewriting rules it provides. As a secondary measure, filter and constrain untrusted input reaching txn_box-processed transactions (for example via upstream WAF/reverse-proxy validation of request fields), accepting that this only reduces rather than removes exposure. Refer to the Apache advisory at https://lists.apache.org/thread/5prl9glcm9g2swnq9hqxvnokylm1gr6d for authoritative guidance.
More in Apache Traffic Server
View allRemote 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
Out-of-bounds write and integer overflow in Apache Traffic Server's MIME and HTTP header parsing lets remote attackers c
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
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
Out-of-bounds write and limit-bypass flaws in several experimental plugins shipped with Apache Traffic Server (8.0.0-8.1
Improper certificate generation in the Apache Traffic Server certifier plugin lets remote attackers dictate the contents
Memory corruption in Apache Traffic Server's remap configuration handling lets remote attackers trigger a use-after-free
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
Out-of-bounds memory write in the Apache Traffic Server header_rewrite plugin allows remote attackers to crash the proxy
Memory corruption in the Cripts scripting framework of Apache Traffic Server (versions 10.0.0 through 10.1.3) allows rem
Denial of service in the Apache Traffic Server ESI (Edge Side Includes) plugin allows remote unauthenticated attackers t
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 memory
Same weakness CWE-121 – Stack-based Buffer Overflow
View allSame technique Buffer Overflow
View allShare
External POC / Exploit Code
Leaving vuln.today
EUVD-2026-50225
GHSA-jxxq-f4qq-497f