Answer in brief
CVE-2026-109821 records a Medium severity (CVSS 6.3) vulnerability in Unbounded port parsing in URI.parse/1 enables CPU exhaustion denial of service in Elixir. The current sources do not mark it as known exploited. The current feed maps elixir-lang/elixir (generic), elixir-lang/elixir-lang/elixir (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps elixir-lang/elixir (generic), elixir-lang/elixir-lang/elixir (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| elixir-lang/elixirgeneric | >=0.5.0 <1.18.6 || >=1.19.0-rc.0 <1.19.7 || >=1.20.0-rc.0 <1.20.5 | 1.18.6, 1.19.7, 1.20.5 |
| elixir-lang/elixir-lang/elixirgeneric | >=39801821eef2d06524e5ebf5a0e4b3c380ad23ae <* | * |
Published upstream
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 30, 2026
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.
Quoted source text, attributed separately from HOL analysis.