Unbounded recursion between Inspect.List charlist rendering and List.to_string/1 error path in Elixir
Summary
| CVE | CVE-2026-75758 |
|---|---|
| State | PUBLISHED |
| Assigner | EEF |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-28 16:18:25 UTC |
| Updated | 2026-08-28 20:19:54 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 5.9 MEDIUM from 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.001260000 probability, percentile 0.026060000 (date 2026-08-31)
Problem Types: CWE-674 | CWE-674 CWE-674 Uncontrolled Recursion
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | Secondary | 5.9 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 5.9 | MEDIUM | CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Elixir-lang | Elixir | affected 1.15.0-rc.0 1.18.5 semver | Not specified |
| CNA | Elixir-lang | Elixir | affected 1.19.0-rc.0 1.19.6 semver | Not specified |
| CNA | Elixir-lang | Elixir | affected 1.20.0-rc.0 1.20.4 semver | Not specified |
| CNA | Elixir-lang | Elixir | affected 9718f2b90ce086ff8614d5782f4ec528495c98dd * git | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| cna.erlef.org/cves/CVE-2026-75758.html | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | cna.erlef.org | |
| github.com/elixir-lang/elixir/security/advisories/GHSA-jf5q-v438-665c | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| github.com/elixir-lang/elixir/commit/5230d73968f1b4969d2a2646786fa6c7147... | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | github.com | |
| github.com/elixir-lang/elixir/commit/0bba5887577b1e328da825bd018815fdc51... | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | github.com | |
| github.com/elixir-lang/elixir/commit/a983c8c043b1fbf1d95df78a29149222dac... | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | github.com | |
| osv.dev/vulnerability/EEF-CVE-2026-75758 | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | osv.dev | |
| github.com/elixir-lang/elixir/commit/1eff1acffd49bdcc0d7f57ca74c1603328e... | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Thomas Cioppettini / Scalpel Software Inc (en)
CNA: José Valim (en)
CNA: Jonatan Männchen / EEF (en)
Additional Advisory Data
Workarounds
CNA: 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.