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era-compiler-vyper First Immutable Variable Initialization vulnerability

Type: advisorySources: OSV

era-compiler-vyper is the EraVM Vyper compiler for zkSync Era, a layer 2 rollup that uses zero-knowledge proofs to scale Ethereum. Prior to era-compiler-vype version 1.3.10, a bug prevented the initialization of the first immutable variable for Vyper contracts meeting certain criteria. The problem arises when there is a String or Array with more 256-bit words allocated than initialized. It results in the second word’s index unset, that is effectively set to 0, so the first immutable value with the actual 0 index is overwritten in the ImmutableSimulator. Version 1.3.10 fixes this issue by setting all indexes in advance. The problem will go away, but it will get more expensive if the user allocates a lot of uninitialized space, e.g. `String[4096]`. Upgrading and redeploying affected contracts is the only way of working around the issue.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2023-46232
Confirmed fixed CVEs
Not specified
Updated in this feed
3 Nov 2026, 15:57 UTC · Revision 1

Source evidence

era-compiler-vyper First Immutable Variable Initialization vulnerability

core-osv · Original source

Published 25 Oct 2023, 21:01 UTC

era-compiler-vyper is the EraVM Vyper compiler for zkSync Era, a layer 2 rollup that uses zero-knowledge proofs to scale Ethereum. Prior to era-compiler-vype version 1.3.10, a bug prevented the initialization of the first immutable variable for Vyper contracts meeting certain criteria. The problem arises when there is a String or Array with more 256-bit words allocated than initialized. It results in the second word’s index unset, that is effectively set to 0, so the first immutable value with the actual 0 index is overwritten in the ImmutableSimulator. Version 1.3.10 fixes this issue by setting all indexes in advance. The problem will go away, but it will get more expensive if the user allocates a lot of uninitialized space, e.g. `String[4096]`. Upgrading and redeploying affected contracts is the only way of working around the issue.

osv:CVE-2023-46232
Complete source record
{
  "id": "0c8ecdb8636720b6f8c93c4c448324234debd1e0da895ac8760b58001b9f861c",
  "url": "https://osv.dev/vulnerability/CVE-2023-46232",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "era-compiler-vyper First Immutable Variable Initialization vulnerability",
    "summary": "era-compiler-vyper is the EraVM Vyper compiler for zkSync Era, a layer 2 rollup that uses zero-knowledge proofs to scale Ethereum. Prior to era-compiler-vype version 1.3.10, a bug prevented the initialization of the first immutable variable for Vyper contracts meeting certain criteria. The problem arises when there is a String or Array with more 256-bit words allocated than initialized. It results in the second word’s index unset, that is effectively set to 0, so the first immutable value with the actual 0 index is overwritten in the ImmutableSimulator. Version 1.3.10 fixes this issue by setting all indexes in advance. The problem will go away, but it will get more expensive if the user allocates a lot of uninitialized space, e.g. `String[4096]`. Upgrading and redeploying affected contracts is the only way of working around the issue.",
    "evidence": "osv:CVE-2023-46232",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2023-46232",
      "aliases": [
        "CVE-2023-46232",
        "GHSA-h8jv-969m-94r4"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/matter-labs/era-compiler-vyper",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "8be305a1b9c68d0fd47dad3434224ed85944ca25"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "8be305a1b9c68d0fd47dad3434224ed85944ca25"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-46232.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.468863333Z",
      "provider": "osv",
      "references": [
        "https://github.com/matter-labs/era-system-contracts/blob/main/contracts/ImmutableSimulator.sol#L37",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/46xxx/CVE-2023-46232.json",
        "https://github.com/matter-labs/era-compiler-vyper/security/advisories/GHSA-h8jv-969m-94r4",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-46232",
        "https://github.com/matter-labs/era-compiler-vyper/commit/8be305a1b9c68d0fd47dad3434224ed85944ca25"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-471"
        ],
        "cna_assigner": "GitHub_M",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "1.3.10"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/46xxx/CVE-2023-46232.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-46232",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 497073,
  "published_at": "2023-10-25T21:01:51.692+00:00"
}