CVE-2026-49762: Unbounded integer parsing in the Version module enables CPU and memory exhaustion denial of service

Severity: medium (CVSS 5.1 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-09 · updated 2026-10-06
Weakness: CWE-400

Description

Uncontrolled Resource Consumption vulnerability in the Elixir standard library's Version module allows an attacker who controls a version string to cause a denial of service through CPU and memory exhaustion. The version parser converts numeric version components (major, minor, patch and numeric pre-release/build identifiers) to integers without bounding their length. A single large all-digit component therefore forces a super-linear, non-yielding base-10 to arbitrary-precision integer conversion (String.to_integer/1, i.e. :erlang.binary_to_integer/1) that pins a BEAM scheduler, and a larger component raises an uncaught SystemLimitError that crashes the calling process. A single moderately sized string (around one megabyte) is enough; no authentication is required. This is reachable from the public entry points Version.parse/1, Version.parse!/1, Version.match?/3, Version.compare/2, and Version.parse_requirement/1, which applications routinely call on untrusted input such as HTTP parameters, dependency-manifest fields, and package metadata. This vulnerability is associated with program files lib/version.ex and program routines 'Elixir.Version.Parser':parse_digits/2. This issue affects elixir: from 0.9.3 before 1.20.1.

Affected products

elixir-lang elixir: from 0.9.3 before 1.20.1 — fixed in 1.20.1

How to fix

Upgrade to a fixed version: elixir-lang elixir 1.20.1. Check the vendor advisory for mitigations.

References

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