Description
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.
Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache Traffic Server | 8.0.0 – ≤ 8.1.11, 9.0.0 – ≤ 9.2.15, 10.0.0 – ≤ 10.1.4, 10.2.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 12 | trafficserver | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | trafficserver | No fix yet | — |
| Ubuntu 18.04 LTS | trafficserver | No fix yet | — |
| Ubuntu 16.04 LTS | trafficserver | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | trafficserver | No fix yet | — |
| Ubuntu Pro 20.04 LTS | trafficserver | No fix yet | — |
Advisories 1
- WID-SEC-2026-4112 Apache Traffic Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 22, 2026
References
- https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc vendor-advisory