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CVE PROGRAM SOURCE RECORD6.3 Medium

CVE-2026-109821

Unbounded port parsing in URI.parse/1 enables CPU exhaustion denial of service in Elixir

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Status
Published
Published
Updated
Assigning organization
EEF

Description

Improper Validation of Specified Quantity in Input vulnerability in the Elixir standard library's URI module allows an attacker who supplies a URL to cause a denial of service through CPU exhaustion. URI.parse/1 converts the port component with String.to_integer/1 in split_authority/1 (lib/elixir/lib/uri.ex) without bounding its length, so a port of up to 1,262,592 decimal digits produces a bignum of that size and a longer one raises SystemLimitError. Rendering the parsed URI back to text (URI.to_string/1, inspect/1, logging, error formatting) converts the bignum with :erlang.integer_to_binary/1, which is quadratic on Erlang/OTP 27, 28 and 29.0: a 400,000-digit port renders in about 2.6 seconds and a 1 MB port in about 18 seconds. Ports above 65535 are also accepted. This issue affects elixir: from 0.5.0 before 1.18.6, from 1.19.0-rc.0 before 1.19.7, and from 1.20.0-rc.0 before 1.20.5.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

elixir-lang elixir

Default version status: unaffected

  • 0.5.0 to < 1.18.6affected
  • 1.19.0-rc.0 to < 1.19.7affected
  • 1.20.0-rc.0 to < 1.20.5affected
pkg:otp/elixir?repository_url=https:%2F%2Fgithub.com%2Felixir-lang%2Felixir&vcs_url=git%2Bhttps:%2F%2Fgithub.com%2Felixir-lang%2Felixir.git

elixir-lang elixir

Default version status: unaffected

  • 39801821eef2d06524e5ebf5a0e4b3c380ad23ae to < *affected
pkg:github/elixir-lang/elixir

References