CVE-2026-40303 (GCVE-0-2026-40303)

Vulnerability from cvelistv5 – Published: 2026-04-17 21:01 – Updated: 2026-04-17 21:01
VLAI?
Title
zrok allows unauthenticated DoS via unbounded memory allocation in striped session cookie parsing
Summary
zrok is software for sharing web services, files, and network resources. Prior to version 2.0.1, endpoints.GetSessionCookie parses an attacker-supplied cookie chunk count and calls make([]string, count) with no upper bound before any token validation occurs. The function is reached on every request to an OAuth-protected proxy share, allowing an unauthenticated remote attacker to trigger gigabyte-scale heap allocations per request, leading to process-level OOM termination or repeated goroutine panics. Both publicProxy and dynamicProxy are affected. Version 2.0.1 patches the issue.
Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-400 - Uncontrolled Resource Consumption
  • CWE-789 - Memory Allocation with Excessive Size Value
Assigner
References
Impacted products
Vendor Product Version
openziti zrok Affected: < 2.0.1
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            "scope": "UNCHANGED",
            "userInteraction": "NONE",
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            "version": "3.1"
          }
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      "providerMetadata": {
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        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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      ],
      "source": {
        "advisory": "GHSA-cpf9-ph2j-ccr9",
        "discovery": "UNKNOWN"
      },
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    }
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  "cveMetadata": {
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    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-40303",
    "datePublished": "2026-04-17T21:01:51.899Z",
    "dateReserved": "2026-04-10T20:22:44.036Z",
    "dateUpdated": "2026-04-17T21:01:51.899Z",
    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
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  }
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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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