CVE-2026-26330: Github.com/envoyproxy/envoy Envoy's Global Rate Limit May Vulnerability

MODERATE
Advisory Identifier: GHSA-c23c-rp3m-vpg3
CVSS 5.3
CWE-416
Published
Advisory Summary

CVE-2026-26330 is a MODERATE (CVSS 5.3) envoy's global rate limit may vulnerability (CWE-416: Use After Free) affecting Github.com/envoyproxy/envoy libraries in the Go ecosystem. The issue involves envoy's global rate limit may crash when the response phase limit is enabled and the response phase request is failed directly. Remediation is available in the latest vendor maintenance releases.

CVE-2026-26330 at a Glance

CVE Identifier CVE-2026-26330
GHSA Identifier GHSA-c23c-rp3m-vpg3
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-416: Use After Free
Affected Product Github.com/envoyproxy/envoy
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-26330

To remediate this vulnerability, upgrade all affected Github.com/envoyproxy/envoy dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/envoyproxy/envoy fixed: Latest secure release
Upgrade github.com/envoyproxy/envoy to Latest secure release
github.com/envoyproxy/envoy fixed: Latest secure release
Upgrade github.com/envoyproxy/envoy to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for github.com/envoyproxy/envoy

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-26330, inspect your project dependencies for Github.com/envoyproxy/envoy:

inspect dependencies for github.com/envoyproxy/envoy

Analyze the terminal output to locate any version of Github.com/envoyproxy/envoy in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-416: Use After Free, where the product reuses or references memory after it has been freed. at some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. In Github.com/envoyproxy/envoy, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary At the rate limit filter, if we enabled the response phase limit with `apply_on_stream_done` in the rate limit configuration and the response phase limit request fails directly, it may crash Envoy. ### Details When both the request phase limit and response phase limit are enabled, the safe gRPC client instance will be re-used for both the request phase request and response phase request. But after the request phase request is done, the inner state of the request phase limit request in gRPC client is not cleaned up. When we send the second limit request at response phase, and the second limit request fails directly, we may access the previous request's inner state and result in crash. ### PoC This need to mock the network failure. But we have reproduced by unit test locally. ### Impact This only happens when both the request phase limit and response phase limit are enabled in the rate limit filter, and requires the request to rate limit service fails directly (For example, if from Envoy's perspective, no healthy endpoint for rate limit service may result the request fails directly). That's say, not easy to trigger this. ### To workaround This could be worked around by splitting the rate limit filter. That is, if there is a rate limit filter that contains normal rate limit configuration (request phase limit, without `apply_on_stream_done`) and also rate limit configuration with `apply_on_stream_done` (response phase limit). Splitting them into two rate limit filters and ensure one filter only contains normal rate limit configuration (without `apply_on_stream_done`), and one only contains rate limit configuration with `apply_on_stream_done` could avoid this problem. ### Credit Mandar Jog (mandarjog@gmail.com)

CVE-2026-26330 Affected Github.com/envoyproxy/envoy Versions

2 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
github.com/envoyproxy/envoy
Go
1.37.0
All 1 versions
1.37.0
None specified
github.com/envoyproxy/envoy
Go
≥ 1.36.0
≤ 1.36.4

References

Frequently Asked Questions

What is CVE-2026-26330?
CVE-2026-26330 is a security vulnerability in Github.com/envoyproxy/envoy involving Envoy's global rate limit may crash when the response phase limit is enabled and the response phase request is failed directly under CWE-416: Use After Free.
Which Github.com/envoyproxy/envoy versions are affected?
Affected versions include releases prior to current release patches across affected packages: github.com/envoyproxy/envoy.
What version fixes CVE-2026-26330?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/envoyproxy/envoy affected?
Yes, github.com/envoyproxy/envoy is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-26330?
CVE-2026-26330 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-26330?
CVE-2026-26330 is classified under CWE-416: Use After Free (The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.).
How can I check Go dependencies for CVE-2026-26330?
Run the dependency tree command: 'inspect dependencies for github.com/envoyproxy/envoy'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c23c-rp3m-vpg3",
  "modified" : "2026-03-10T22:54:51Z",
  "published" : "2026-03-10T18:31:57Z",
  "aliases" : [ "CVE-2026-26330" ],
  "summary" : "Envoy's global rate limit may crash when the response phase limit is enabled and the response phase request is failed directly",
  "details" : "### Summary\n\nAt the rate limit filter, if we enabled the response phase limit with `apply_on_stream_done` in the rate limit configuration and the response phase limit request fails directly, it may crash Envoy.\n\n### Details\n\nWhen both the request phase limit and response phase limit are enabled, the safe gRPC client instance will be re-used for both the request phase request and response phase request.\n\nBut after the request phase request is done, the inner state of the request phase limit request in gRPC client is not cleaned up. When we send the second limit request at response phase, and the second limit request fails directly, we may access the previous request's inner state and result in crash.\n\n\n### PoC\n\nThis need to mock the network failure. But we have reproduced by unit test locally.\n\n### Impact\n\nThis only happens when both the request phase limit and response phase limit are enabled in the rate limit filter, and requires the request to rate limit service fails directly (For example, if from Envoy's perspective, no healthy endpoint for rate limit service may result the request fails directly). That's say, not easy to trigger this.\n\n### To workaround\n\nThis could be worked around by splitting the rate limit filter. That is, if there is a rate limit filter that contains normal rate limit configuration (request phase limit, without `apply_on_stream_done`) and also rate limit configuration with `apply_on_stream_done` (response phase limit). Splitting them into two rate limit filters and ensure one filter only contains normal rate limit configuration (without `apply_on_stream_done`), and one only contains rate limit configuration with `apply_on_stream_done` could avoid this problem. \n\n### Credit\n\nMandar Jog (mandarjog@gmail.com)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/envoyproxy/envoy"
    },
    "versions" : [ "1.37.0" ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/envoyproxy/envoy"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.36.0"
      }, {
        "last_affected" : "1.36.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/envoyproxy/envoy/security/advisories/GHSA-c23c-rp3m-vpg3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-26330"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/envoyproxy/envoy"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-416" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-10T18:31:57Z",
    "nvd_published_at" : "2026-03-10T20:16:36Z"
  }
}