CVE-2026-65100: CWE-696 Incorrect Behavior Order in Apache Software Foundation Apache Traffic Server
Apache Traffic Server versions 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, and 10.0.0 through 10.1.3 have a vulnerability where the HTTP/2 HPACK dynamic table is updated before confirming successful header block encoding. This can cause the encoder to become out of sync with the peer decoder if encoding fails, leading to corruption of subsequent header blocks on the connection. Upgrading to versions 9.2.15 or 10.1.4 addresses this issue.
AI Analysis
Technical Summary
The vulnerability in Apache Traffic Server involves incorrect behavior order in handling HTTP/2 HPACK dynamic table updates. Specifically, the server updates the dynamic table before confirming that the header block encoding succeeded. If encoding fails, this results in the encoder and peer decoder becoming unsynchronized, corrupting subsequent header blocks on the connection. This affects Apache Traffic Server versions 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, and 10.0.0 through 10.1.3. The issue is fixed in versions 9.2.15 and 10.1.4.
Potential Impact
The vulnerability can cause the HTTP/2 connection to become corrupted due to desynchronization between the encoder and decoder, potentially leading to denial of service or degraded communication reliability. There is no indication of confidentiality or availability impact beyond this corruption. The CVSS score of 4.8 reflects a medium severity with low impact on confidentiality, limited impact on integrity, and low impact on availability.
Mitigation Recommendations
Users should upgrade Apache Traffic Server to version 9.2.15 or 10.1.4 or later to remediate this vulnerability. No other mitigation or temporary workaround is indicated. Patch status is confirmed by the vendor advisory recommending these fixed versions.
CVE-2026-65100: CWE-696 Incorrect Behavior Order in Apache Software Foundation Apache Traffic Server
Description
Apache Traffic Server versions 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, and 10.0.0 through 10.1.3 have a vulnerability where the HTTP/2 HPACK dynamic table is updated before confirming successful header block encoding. This can cause the encoder to become out of sync with the peer decoder if encoding fails, leading to corruption of subsequent header blocks on the connection. Upgrading to versions 9.2.15 or 10.1.4 addresses this issue.
CVSS v3.1
Score 4.8medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Apache Traffic Server involves incorrect behavior order in handling HTTP/2 HPACK dynamic table updates. Specifically, the server updates the dynamic table before confirming that the header block encoding succeeded. If encoding fails, this results in the encoder and peer decoder becoming unsynchronized, corrupting subsequent header blocks on the connection. This affects Apache Traffic Server versions 8.0.0 through 8.1.9, 9.0.0 through 9.2.14, and 10.0.0 through 10.1.3. The issue is fixed in versions 9.2.15 and 10.1.4.
Potential Impact
The vulnerability can cause the HTTP/2 connection to become corrupted due to desynchronization between the encoder and decoder, potentially leading to denial of service or degraded communication reliability. There is no indication of confidentiality or availability impact beyond this corruption. The CVSS score of 4.8 reflects a medium severity with low impact on confidentiality, limited impact on integrity, and low impact on availability.
Mitigation Recommendations
Users should upgrade Apache Traffic Server to version 9.2.15 or 10.1.4 or later to remediate this vulnerability. No other mitigation or temporary workaround is indicated. Patch status is confirmed by the vendor advisory recommending these fixed versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-07-21T17:10:18.202Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a69c9f59c2644c7f8487ef3
Added to database: 07/29/2026, 09:37:57 UTC
Last enriched: 07/29/2026, 10:23:45 UTC
Last updated: 07/29/2026, 10:23:45 UTC
Views: 5
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