CVE-2026-21619: Erlang REBAR3

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Uncontrolled Resource Consumption, Deserialization of Untrusted Data vulnerability in hexpm hex_core (hex_api modules), hexpm hex (mix_hex_api modules), erlang rebar3 (r3_hex_api modules) allows Object Injection, Excessive Allocation. This vulnerability is associated with program files src/hex_api.erl, src/mix_hex_api.erl, apps/rebar/src/vendored/r3_hex_api.erl and program routines hex_core:request/4, mix_hex_api:request/4, r3_hex_api:request/4. This issue affects hex_core: from 0.1.0 before 0.12.1; hex: from 2.3.0 before 2.3.2; rebar3: from 3.9.1 before 3.27.0.

Affected products

• Erlang REBAR3: from 3.9.1, before 3.27.0 (fixed in 3.27.0)
• Hex Hex: from 2.3.0, before 2.3.2 (fixed in 2.3.2)
• Hex Hex Core: from 0.1.0, before 0.12.1 (fixed in 0.12.1)

Published 2026-02-27. Last modified 2026-06-17.