Vulnerability-Lookup

CVE-2026-0994 (GCVE-0-2026-0994)

Vulnerability from cvelistv5 – Published: 2026-01-23 14:55 – Updated: 2026-01-23 15:34

Title

Denial of Service in Python Protobuf

Summary

A denial-of-service (DoS) vulnerability exists in google.protobuf.json_format.ParseDict() in Python, where the max_recursion_depth limit can be bypassed when parsing nested google.protobuf.Any messages. Due to missing recursion depth accounting inside the internal Any-handling logic, an attacker can supply deeply nested Any structures that bypass the intended recursion limit, eventually exhausting Python’s recursion stack and causing a RecursionError.

Severity ?

8.2 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

CWE

CWE-674 - Uncontrolled Recursion

Assigner

Google

References

URL

Tags

https://github.com/protocolbuffers/protobuf/pull/25239

Impacted products

	Vendor	Product	Version
	Python	Protobuf	Affected: >= V33.0 (custom)

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-0994

Vulnerability from fkie_nvd - Published: 2026-01-23 15:16 - Updated: 2026-01-23 15:16

Severity ?

8.2 (High) - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

Summary

References

	URL	Tags
	cve-coordination@google.com	https://github.com/protocolbuffers/protobuf/pull/25239

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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      "lang": "en",
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    }
  ],
  "id": "CVE-2026-0994",
  "lastModified": "2026-01-23T15:16:06.840",
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GHSA-7GCM-G887-7QV7

Vulnerability from github – Published: 2026-01-23 15:31 – Updated: 2026-01-23 16:56

Summary

protobuf affected by a JSON recursion depth bypass

Details

Due to missing recursion depth accounting inside the internal Any-handling logic, an attacker can supply deeply nested Any structures that bypass the intended recursion limit, eventually exhausting Python’s recursion stack and causing a RecursionError.

Severity ?

8.2 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

Show details on source website

JSON

To clipboard

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      "package": {
        "ecosystem": "PyPI",
        "name": "protobuf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "6.33.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-0994"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-01-23T16:56:33Z",
    "nvd_published_at": "2026-01-23T15:16:06Z",
    "severity": "HIGH"
  },
  "details": "A denial-of-service (DoS) vulnerability exists in google.protobuf.json_format.ParseDict() in Python, where the max_recursion_depth limit can be bypassed when parsing nested google.protobuf.Any messages.\n\nDue to missing recursion depth accounting inside the internal Any-handling logic, an attacker can supply deeply nested Any structures that bypass the intended recursion limit, eventually exhausting Python\u2019s recursion stack and causing a RecursionError.",
  "id": "GHSA-7gcm-g887-7qv7",
  "modified": "2026-01-23T16:56:33Z",
  "published": "2026-01-23T15:31:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-0994"
    },
    {
      "type": "WEB",
      "url": "https://github.com/protocolbuffers/protobuf/issues/25070"
    },
    {
      "type": "WEB",
      "url": "https://github.com/protocolbuffers/protobuf/pull/25239"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/protocolbuffers/protobuf"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L",
      "type": "CVSS_V4"
    }
  ],
  "summary": "protobuf affected by a JSON recursion depth bypass"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-0994 (GCVE-0-2026-0994)

FKIE_CVE-2026-0994

GHSA-7GCM-G887-7QV7

Tags

Sightings

Nomenclature