Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-07-27T15:13:54 erlang-otp: Erlang OTP: Denial of Service via crafted external term format binary 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CWE-787

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. When 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. This 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.

A flaw was found in Erlang OTP. A remote attacker can exploit a vulnerability in the Erlang external term format (ETF) decoder by providing a specially crafted binary to the binary_to_term/1 function. This manipulation of data types during processing can corrupt the system's memory, leading to an out-of-bounds write. The ultimate consequence is a denial of service (DoS), causing the Erlang virtual machine to crash.

Red Hat Hardened Images Not affected erlang27 https://www.cve.org/CVERecord?id=CVE-2026-55737 https://nvd.nist.gov/vuln/detail/CVE-2026-55737 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