The BIT_BINARY_EXT tag (77) handler in the External Term Format (ETF) decoder accepts an encoding with both length and trailing-bits fields set to zero. The subsequent computation of the bitstring size underflows an unsigned integer, producing a value of roughly 2^64 that is then passed as a memory allocation size. The allocator aborts the entire node with a message such as Cannot allocate 2305843009213693951 bytes of memory (of type \"binary\").
The crash is a VM-level abort, not an Erlang-level exception. It cannot be intercepted by supervision trees, by try/catch, or by passing the [safe] option to binary_to_term/2 (which only restricts atom creation and does not perform structural validation of binary encodings).
Any application that decodes ETF from untrusted sources via binary_to_term/1,2 or enif_binary_to_term() is exposed. The Erlang distribution protocol also decodes incoming terms through the same code path, but distribution is expected to run on trusted networks per the OTP Secure Coding Guidelines (DSG-011).
This issue affects OTP from OTP 27.0 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to erts from 15.0 before 17.0.4, 16.4.0.4 and 15.2.7.11.
" } ], "value": "Integer Underflow (Wrap or Wraparound) vulnerability in erlang otp erlang/otp (erts modules), erlang otp erts (erts modules) allows Forced Integer Overflow, Excessive Allocation. This vulnerability is associated with program files erts/emulator/beam/external.c, emulator/beam/external.c.\n\nThe BIT_BINARY_EXT tag (77) handler in the External Term Format (ETF) decoder accepts an encoding with both length and trailing-bits fields set to zero. The subsequent computation of the bitstring size underflows an unsigned integer, producing a value of roughly 2^64 that is then passed as a memory allocation size. The allocator aborts the entire node with a message such as \"Cannot allocate 2305843009213693951 bytes of memory (of type binary)\".\n\nThe crash is a VM-level abort, not an Erlang-level exception. It cannot be intercepted by supervision trees, by try/catch, or by passing the [safe] option to binary_to_term/2 (which only restricts atom creation and does not perform structural validation of binary encodings).\n\nAny application that decodes ETF from untrusted sources via binary_to_term/1,2 or enif_binary_to_term() is exposed. The Erlang distribution protocol also decodes incoming terms through the same code path, but distribution is expected to run on trusted networks per the OTP Secure Coding Guidelines (DSG-011).\n\nThis issue affects OTP from OTP 27.0 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to erts from 15.0 before 17.0.4, 16.4.0.4 and 15.2.7.11." } ], "impacts": [ { "capecId": "CAPEC-92", "descriptions": [ { "lang": "en", "value": "CAPEC-92 Forced Integer Overflow" } ] }, { "capecId": "CAPEC-130", "descriptions": [ { "lang": "en", "value": "CAPEC-130 Excessive Allocation" } ] } ], "metrics": [ { "cvssV4_0": { "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "baseScore": 8.2, "baseSeverity": "HIGH", "privilegesRequired": "NONE", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE" }, "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ] } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-191", "description": "CWE-191 Integer Underflow (Wrap or Wraparound)", "lang": "en", "type": "CWE" }, { "cweId": "CWE-789", "description": "CWE-789 Memory Allocation with Excessive Size Value", "lang": "en", "type": "CWE" }, { "cweId": "CWE-1284", "description": "CWE-1284 Improper Validation of Specified Quantity in Input", "lang": "en", "type": "CWE" } ] } ], "providerMetadata": { "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-07-28T09:55:08.138Z" }, "references": [ { "tags": [ "vendor-advisory", "related" ], "url": "https://github.com/erlang/otp/security/advisories/GHSA-54pw-5645-jh86" }, { "tags": [ "related" ], "url": "https://cna.erlef.org/cves/CVE-2026-54890.html" }, { "tags": [ "related" ], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-54890" }, { "tags": [ "x_version-scheme" ], "url": "https://www.erlang.org/doc/system/versions.html#order-of-versions" }, { "tags": [ "patch" ], "url": "https://github.com/erlang/otp/commit/dc1bf9344c0ce62717cf60866590cea0242780fd" } ], "source": { "discovery": "EXTERNAL" }, "title": "BEAM VM crash via integer underflow in binary_to_term BIT_BINARY_EXT decoding", "workarounds": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "Do not call binary_to_term/1,2 or enif_binary_to_term() on data from untrusted sources. The OTP Secure Coding Guidelines (DSG-011) recommend avoiding these functions altogether on untrusted input and using an alternative serialization format (for example JSON or Protocol Buffers) instead.
" } ], "value": "Do not call binary_to_term/1,2 or enif_binary_to_term() on data from untrusted sources. The OTP Secure Coding Guidelines (DSG-011) recommend avoiding these functions altogether on untrusted input and using an alternative serialization format (for example JSON or Protocol Buffers) instead." } ], "x_generator": { "engine": "cvelib 1.8.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-07-27T18:18:57.223218Z", "id": "CVE-2026-54890", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-27T18:19:08.876Z" } } ] } }