Stack Buffer Overflow in ei_s_print_term at Very Large Integer

Open Source Vulnerabilities CVE-2026-49760

Stack-based Buffer Overflow vulnerability in Erlang OTP (erl_interface) allows Stack-based Buffer Overflow. This vulnerability is associated with program file lib/erl_interface/src/misc/ei_printterm.c and program routine ei_s_print_term. The C function ei_s_print_term uses an internal 2000-character stack buffer to format terms. When called with an encoded Erlang term containing a very large integer (encoded representation exceeding 2000 characters), the buffer overflows. The overflow bytes are restricted to the ASCII values of 0-9 and A-F, which limits exploitation to Denial of Service. The companion function ei_print_term, which prints directly to a FILE instead of a memory buffer, does not contain this bug. This issue affects OTP from OTP 17.0 before OTP 29.0.2, OTP 28.5.0.2 and OTP 27.3.4.13, corresponding to erl_interface from 3.7.16 before 5.8.1, 5.7.0.1 and 5.5.2.1.

Open Source Vulnerabilities EEF-CVE-2026-49760

## Summary Stack-based Buffer Overflow vulnerability in Erlang OTP (erl\_interface) allows Stack-based Buffer Overflow. This vulnerability is associated with program file lib/erl\_interface/src/misc/ei\_printterm.c and program routine ei\_s\_print\_term. The C function ei\_s\_print\_term uses an internal 2000-character stack buffer to format terms. When called with an encoded Erlang term containing a very large integer (encoded representation exceeding 2000 characters), the buffer overflows. The overflow bytes are restricted to the ASCII values of 0-9 and A-F, which limits exploitation to Denial of Service. The companion function ei\_print\_term, which prints directly to a FILE instead of a memory buffer, does not contain this bug. This issue affects OTP from OTP 17.0 before OTP 29.0.2, OTP 28.5.0.2 and OTP 27.3.4.13, corresponding to erl\_interface from 3.7.16 before 5.8.1, 5.7.0.1 and 5.5.2.1. ## Workaround Avoid calling ei\_s\_print\_term with untrusted data whose encoded integer representation could exceed 2000 characters.