Inspect.List's charlist branch in lib/elixir/lib/inspect.ex classifies a list as a charlist using List.ascii_printable?/2, which examines only the first :printable_limit (4096 by default) elements, and then calls IO.chardata_to_string/1 on the whole term. A list whose printable prefix exceeds that limit but which contains a later element that is not a code point (an atom, an out-of-range integer, or an improper tail) is therefore mis-classified, and the conversion raises ArgumentError. That conversion runs inside List.to_string/1, whose rescue clause builds its message by interpolating inspect(list), which re-enters the same branch and raises again. The nested inspection is an argument to raise, so the recursion is not in tail position and every level is retained: the process stack grows monotonically while each cycle re-walks the list, until the process is killed by max_heap_size or, by default, the node runs out of memory. List.to_charlist/1 has the same rescue shape.
Below the printable limit the inner inspect/1 sees the invalid element within its counter and renders the list in ordinary bracket form, so a single ArgumentError is raised and no recursion occurs.
This issue affects elixir: from 1.15.0-rc.0 before 1.18.5, from 1.19.0-rc.0 before 1.19.6, and from 1.20.0-rc.0 before 1.20.4.
Analysis
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||
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| elixir-lang | elixir | unaffected |
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| elixir-lang | elixir | unaffected |
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Vendor Workaround
Install a global inspect function that renders lists as lists rather than inferring charlists, by calling Inspect.Opts.default_inspect_fun/1 with fn term, opts -> Inspect.inspect(term, %{opts | charlists: :as_lists}) end from the application's start callback. This keeps the charlist branch from being entered at all, so the mis-inferred conversion never raises and the error path cannot recurse. The trade-off is global: charlists then render in bracket form, so ~c"abc" inspects as [97, 98, 99] everywhere in the application, including in logs and error reports.
Tracking
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Fri, 28 Aug 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Uncontrolled Recursion vulnerability in the Elixir standard library allows an attacker who controls a list passed to inspect/1, List.to_string/1, or List.to_charlist/1 to exhaust a BEAM node's memory. Inspect.List's charlist branch in lib/elixir/lib/inspect.ex classifies a list as a charlist using List.ascii_printable?/2, which examines only the first :printable_limit (4096 by default) elements, and then calls IO.chardata_to_string/1 on the whole term. A list whose printable prefix exceeds that limit but which contains a later element that is not a code point (an atom, an out-of-range integer, or an improper tail) is therefore mis-classified, and the conversion raises ArgumentError. That conversion runs inside List.to_string/1, whose rescue clause builds its message by interpolating inspect(list), which re-enters the same branch and raises again. The nested inspection is an argument to raise, so the recursion is not in tail position and every level is retained: the process stack grows monotonically while each cycle re-walks the list, until the process is killed by max_heap_size or, by default, the node runs out of memory. List.to_charlist/1 has the same rescue shape. Below the printable limit the inner inspect/1 sees the invalid element within its counter and renders the list in ordinary bracket form, so a single ArgumentError is raised and no recursion occurs. This issue affects elixir: from 1.15.0-rc.0 before 1.18.5, from 1.19.0-rc.0 before 1.19.6, and from 1.20.0-rc.0 before 1.20.4. | |
| Title | Unbounded recursion between Inspect.List charlist rendering and List.to_string/1 error path in Elixir | |
| First Time appeared |
Elixir-lang
Elixir-lang elixir |
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| Weaknesses | CWE-674 | |
| CPEs | cpe:2.3:a:elixir-lang:elixir:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Elixir-lang
Elixir-lang elixir |
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| References |
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| Metrics |
cvssV4_0
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MITRE
Status: PUBLISHED
Assigner: EEF
Published:
Updated: 2026-08-28T11:28:53.505Z
Reserved: 2026-08-19T09:00:01.955Z
Link: CVE-2026-75758
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-08-28T16:18:25.277
Modified: 2026-08-28T16:18:25.277
Link: CVE-2026-75758
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-08-28T17:00:13Z