# CVE-2026-32686: ericmj decimal denial of service via unbounded exponent

Source: https://junglewise.ai/threats/cve-2026-32686-ericmj-decimal-denial-of-service-via-unbounded-exponent  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-07. Updated: 2026-08-05  
License: CC BY 4.0 with a link back

CVE-2026-32686 · Severity: medium · CVSS 6.9 · Published 2026-05-07

A vulnerability in the 'decimal' library, commonly used in Elixir and Erlang applications to handle precise math, allows an attacker to crash a server. By providing a specially crafted number with an extremely large exponent, an attacker can force the application to consume all available memory. This results in a denial-of-service (DoS) where the application becomes unresponsive or shuts down entirely.

Vendors: [Erlang](https://junglewise.ai/threats/vendors/erlang).

## Quick answers

**Is CVE-2026-32686 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-32686 being exploited in the wild.

**How severe is CVE-2026-32686?** Medium severity, with a CVSS score of 6.9, published 7 May 2026.

**Which products and versions are affected?** Erlang Decimal >= 0.1.0, < 3.0.0.

**Is there a fix for CVE-2026-32686?** A patch was published on 2026-05-07: Initial patch in 3.0.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-32686 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-32686?** Check whether you run Erlang Decimal at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The 'decimal' library does not bound the exponent on parsed input in functions like `Decimal.new/parse/cast`. When arithmetic operations (add, sub, div), rounding, or string conversions are performed on these decimals, the library uses tail-recursion or list duplication proportional to the exponent's value. For example, a positive exponent causes the library to grow a bignum coefficient by one digit per iteration, rapidly exhausting memory. An unauthenticated remote attacker can exploit this by submitting a large exponent (e.g., "1e10000000") via JSON, form fields, or database entries that the application subsequently processes. This vulnerability is fully patched in version 3.0.0; while version 2.4.0 contains mitigations, they are not enabled by default.

## Affected products

- ericmj decimal >= 0.1.0, < 3.0.0

## Identifiers

- CVE-2026-32686
- GHSA-rhv4-8758-jx7v

## Timeline

- 2026-05-07: disclosed
- 2026-05-07: patched: Initial patch in 3.0.0
- 2026-05-12: advisory

## References

- [https://api.github.com/users/PJUllrich](https://api.github.com/users/PJUllrich)
- [https://github.com/PJUllrich](https://github.com/PJUllrich)
- [https://api.github.com/users/PJUllrich/gists%7B/gist_id%7D](https://api.github.com/users/PJUllrich/gists%7B/gist_id%7D)
- [https://api.github.com/users/PJUllrich/repos](https://api.github.com/users/PJUllrich/repos)
- [https://avatars.githubusercontent.com/u/10426523?v=4](https://avatars.githubusercontent.com/u/10426523?v=4)
- [https://api.github.com/users/PJUllrich/events%7B/privacy%7D](https://api.github.com/users/PJUllrich/events%7B/privacy%7D)