{"cve":"CVE-2026-55737","nvd":{"published":"2026-07-27T16:17:48.847","modified":"2026-10-24T13:10:00.147","status":"Analyzed","description":"Signed to Unsigned Conversion Error and Out-of-bounds Write vulnerability in Erlang OTP erts allows an attacker who can supply a crafted Erlang external term format (ETF) binary to binary_to_term/1 to corrupt the BEAM heap pointer and crash the virtual machine.\n\nWhen decoding a LARGE_TUPLE_EXT term, the validation pass decoded_size() in erts/emulator/beam/external.c reads the 32-bit arity field as unsigned (get_uint32()), while the decode pass dec_term() reads the same field as a signed 32-bit integer (get_int32()) into an int. An arity wire value of 0x80000000 passes validation as 2147483648 but decodes as -2147483648, so the subsequent hp += n moves the heap allocation pointer backward. Neither pass enforces the runtime tuple-arity limit MAX_ARITYVAL. The result is an out-of-bounds heap write; in practice the VM detects an impossible heap size and aborts, denying service. The required padding is large when uncompressed but the compressed-ETF envelope shrinks it to a small payload on the wire.\n\nThis issue affects OTP from OTP 25.0 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15, corresponding to erts from 13.0 before 17.0.4, 16.4.0.4 and 15.2.7.11.","cvss_v4":{"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","score":5.1},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-195","CWE-787"],"references":["https://cna.erlef.org/cves/CVE-2026-55737.html","https://github.com/erlang/otp/commit/c5210b42a9d3d96f3d25601942ce8122be0f3761","https://github.com/erlang/otp/security/advisories/GHSA-446w-268v-9462","https://osv.dev/vulnerability/EEF-CVE-2026-55737","https://www.erlang.org/doc/system/versions.html#order-of-versions"],"products":["erlang:erlang\\/otp","erlang:erts"],"source":"nvd","synced_at":"2026-10-24T16:53:27.712498749+00:00"},"epss":{"cve":"CVE-2026-55737","score":0.00288,"percentile":0.21161,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}