Description
Apache Traffic Server updates the HTTP/2 HPACK dynamic table before confirming the header block encoded successfully, so an encode failure leaves the encoder out of sync with the peer decoder and corrupts subsequent header blocks on the connection.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, 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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache Traffic Server | 8.0.0 – ≤ 8.1.11, 9.0.0 – ≤ 9.2.14, 10.0.0 – ≤ 10.1.3 | — |
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-2026-2561 Apache Traffic Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jul 29, 2026
References
- https://lists.apache.org/thread/5prl9glcm9g2swnq9hqxvnokylm1gr6d vendor-advisory