CVE-2026-49760: Stack Buffer Overflow in ei_s_print_term at Very Large Integer

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-10 · updated 2026-10-26
Weakness: CWE-121

Description

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 27.3.4.13, OTP 28.5.0.2, and OTP 29.0.2, corresponding to erl_interface from 3.7.16 before 5.5.2.1, 5.7.0.1, and 5.8.1. Whether OTP before OTP 17.0, corresponding to erl_interface before 3.7.16, is affected is unknown.

Affected products

Erlang Erl Interface: from 3.7.16 before 5.5.2.1; from 5.7 before 5.7.0.1; from 5.8 before 5.8.1 — fixed in 5.5.2.1, 5.7.0.1, 5.8.1
Erlang OTP: from 17.0 before 27.3.4.13; from 28.0 before 28.5.0.2; from 29.0 before 29.0.2 — fixed in 27.3.4.13, 28.5.0.2, 29.0.2

How to fix

Upgrade to a fixed version: Erlang Erl Interface 5.5.2.1, 5.7.0.1, 5.8.1; Erlang OTP 27.3.4.13, 28.5.0.2, 29.0.2. Check the vendor advisory for mitigations.

References

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