# tinfoil-factory netfoil resource leak in LRU cache

Source: https://junglewise.ai/threats/tinfoil-factory-netfoil-resource-leak-in-lru-cache-b447cb08  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-07. Updated: 2026-07-07  
License: CC BY 4.0 with a link back

Severity: low · CVSS 1.2 · Published 2026-07-07

A memory leak exists in the netfoil library's caching mechanism. A local attacker can exploit this to force the application to consume excessive memory, potentially leading to service restarts and temporary unavailability if memory limits are reached.

Technologies: [github.com/tinfoil-factory/netfoil (Go)](https://junglewise.ai/threats/technologies/github-com-tinfoil-factory-netfoil), [Tinfoil Factory Netfoil](https://junglewise.ai/threats/technologies/netfoil). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Tinfoil Factory](https://junglewise.ai/threats/vendors/tinfoil-factory).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Low severity, with a CVSS score of 1.2, published 7 July 2026.

**Which products and versions are affected?** github.com/tinfoil-factory/netfoil (Go) < 0.3.0; Tinfoil Factory Netfoil < 0.3.0.

**Is there a fix for This vulnerability?** A patch was published on 2026-07-07: Fix available in version 0.3.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked with local access, in a software library.

**Am I affected?** Check whether you run github.com/tinfoil-factory/netfoil (Go) or Tinfoil Factory Netfoil 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

A memory leak (CWE-401) exists in the netfoil LRU cache implementation. When an entry is removed from the cache, a pointer to the removed element is not properly cleaned up, preventing the memory from being reclaimed. A local attacker can trigger this leak to increase the process's memory footprint. In environments using systemd with default memory limits (e.g., 100MB), this will eventually trigger an Out-Of-Memory (OOM) kill or service restart, resulting in a local denial-of-service. The issue is fixed in version 0.3.0.

## Affected products

- tinfoil-factory netfoil < 0.3.0

## Timeline

- 2026-05-31: disclosed: Initial disclosure by tinfoil-owner
- 2026-07-07: advisory: GitHub Advisory published
- 2026-07-07: patched: Fix available in version 0.3.0

## References

- [https://api.github.com/users/stigtsp](https://api.github.com/users/stigtsp)
- [https://github.com/stigtsp](https://github.com/stigtsp)
- [https://api.github.com/users/stigtsp/gists%7B/gist_id%7D](https://api.github.com/users/stigtsp/gists%7B/gist_id%7D)
- [https://api.github.com/users/stigtsp/repos](https://api.github.com/users/stigtsp/repos)
- [https://avatars.githubusercontent.com/u/75371?v=4](https://avatars.githubusercontent.com/u/75371?v=4)
- [https://api.github.com/users/stigtsp/events%7B/privacy%7D](https://api.github.com/users/stigtsp/events%7B/privacy%7D)

## Related threats

- [Netfoil TTL not decremented in DNS responses](https://junglewise.ai/threats/go-2026-6906-netfoil-doesn-t-decrement-ttl-in-github-com-tinfoil-a5094761)
- [Netfoil TTL decrement logic flaw](https://junglewise.ai/threats/netfoil-doesn-t-decrement-ttl-f0272cfd)
- [GO-2026-6277 - netfoil vulnerable to improper handling of untrusted DoH response data in github.com/tinfoil-factory/netfoil](https://junglewise.ai/threats/go-2026-6277-netfoil-vulnerable-to-improper-handling-of-untrusted-doh-3c188b0a)
- [netfoil improper output neutralization for logs in DoH response handling](https://junglewise.ai/threats/netfoil-improper-output-neutralization-for-logs-in-doh-response-c6a8161c)
- [GO-2026-6143 - netfoil: Incorrect block responses could lead to localhost traffic in github.com/tinfoil-factory/netfoil](https://junglewise.ai/threats/go-2026-6143-netfoil-incorrect-block-responses-could-lead-to-localhost-10a9eea0)