CVE-2026-73513: CWE-20: Improper Input Validation in envoyproxy envoy
Envoy proxy versions prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1 contain a vulnerability in the optional oghttp2 upstream HTTP/2 codec. This flaw allows a response trailer HEADERS frame without END_STREAM to cause a use-after-free condition, leading to a process crash. The issue arises because Envoy completes and deletes the ActiveRequest while the oghttp2 codec keeps the stream open, resulting in a dangling pointer. This vulnerability is fixed in the specified patched versions.
AI Analysis
Technical Summary
CVE-2026-73513 describes an improper input validation vulnerability (CWE-20) and use-after-free (CWE-416) in Envoy's optional oghttp2 upstream HTTP/2 codec. When Envoy receives a response trailer HEADERS frame lacking the END_STREAM flag, it prematurely completes and deletes the ActiveRequest object, but the oghttp2 codec continues to keep the stream open. This leads to a dangling reference in ClientStreamImpl's response_decoder_, which can be accessed by subsequent frames, causing a crash of the Envoy process. The default nghttp2 codec does not exhibit this behavior as it rejects malformed trailers. The vulnerability affects specific versions before 1.36.10, 1.37.6, 1.38.4, and 1.39.1, where the issue has been fixed.
Potential Impact
Successful exploitation results in a denial of service due to a process crash caused by a use-after-free condition. There is no indication of confidentiality or integrity impact. The vulnerability requires no privileges or user interaction and can be triggered remotely via upstream HTTP/2 traffic when oghttp2 codec is enabled.
Mitigation Recommendations
This vulnerability is fixed in Envoy versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1. Users should upgrade to these or later versions to remediate the issue. No other mitigation or workaround is indicated in the available data.
CVE-2026-73513: CWE-20: Improper Input Validation in envoyproxy envoy
Description
Envoy proxy versions prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1 contain a vulnerability in the optional oghttp2 upstream HTTP/2 codec. This flaw allows a response trailer HEADERS frame without END_STREAM to cause a use-after-free condition, leading to a process crash. The issue arises because Envoy completes and deletes the ActiveRequest while the oghttp2 codec keeps the stream open, resulting in a dangling pointer. This vulnerability is fixed in the specified patched versions.
CVSS v3.1
Score 7.5high
Affected software
envoyproxy
envoy
pkg:github/envoyproxy/envoyRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-73513 describes an improper input validation vulnerability (CWE-20) and use-after-free (CWE-416) in Envoy's optional oghttp2 upstream HTTP/2 codec. When Envoy receives a response trailer HEADERS frame lacking the END_STREAM flag, it prematurely completes and deletes the ActiveRequest object, but the oghttp2 codec continues to keep the stream open. This leads to a dangling reference in ClientStreamImpl's response_decoder_, which can be accessed by subsequent frames, causing a crash of the Envoy process. The default nghttp2 codec does not exhibit this behavior as it rejects malformed trailers. The vulnerability affects specific versions before 1.36.10, 1.37.6, 1.38.4, and 1.39.1, where the issue has been fixed.
Potential Impact
Successful exploitation results in a denial of service due to a process crash caused by a use-after-free condition. There is no indication of confidentiality or integrity impact. The vulnerability requires no privileges or user interaction and can be triggered remotely via upstream HTTP/2 traffic when oghttp2 codec is enabled.
Mitigation Recommendations
This vulnerability is fixed in Envoy versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1. Users should upgrade to these or later versions to remediate the issue. No other mitigation or workaround is indicated in the available data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-12T19:00:33.737Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ab1abbd55bf5e2cf58b468f
Added to database: 09/21/2026, 22:12:13 UTC
Last enriched: 09/21/2026, 22:15:02 UTC
Last updated: 09/22/2026, 00:43:18 UTC
Views: 5
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