# CVE-2026-38641: Redox OS relibc denial of service in DSO::mmap_and_copy

Source: https://junglewise.ai/threats/cve-2026-38641-redox-os-relibc-denial-of-service-in-dso-mmap-and-copy  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-26. Updated: 2026-06-26  
License: CC BY 4.0 with a link back

CVE-2026-38641 · Severity: info · Published 2026-06-26

Relibc is a standard C library used by the Redox operating system to handle core system functions, including loading external software modules. A vulnerability exists where the library fails to properly handle malformed files when a program tries to load a shared library. An attacker could use a specially crafted file to cause the application to crash, resulting in a denial of service.

Technologies: [Redox OS Relibc](https://junglewise.ai/threats/technologies/relibc). Vendors: [Redox OS](https://junglewise.ai/threats/vendors/redox-os).

## Quick answers

**Is CVE-2026-38641 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-38641 being exploited in the wild.

**How severe is CVE-2026-38641?** Informational severity, published 26 June 2026.

**Which products and versions are affected?** Redox OS Relibc commit 61f42d6b93adc552a9e8b6f207fca907e8ca8be2.

**Is there a fix for CVE-2026-38641?** A patch was published on 2026-02-27: Merge request 1046 submitted to fix the issue Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-38641 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-38641?** Check whether you run Redox OS Relibc 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 reachable unwrap panic exists in the DSO::mmap_and_copy function within src/ld_so/dso.rs of relibc (specifically commit 61f42d). The vulnerability is triggered when the dlopen() function is called on a malformed ELF shared library that does not contain a PT_LOAD segment. Because the code uses .unwrap() on a Result that returns an error in this scenario, the process terminates with a panic. This allows a local attacker to cause a denial of service (DoS) of any process that can be induced to load an arbitrary library file. A fix has been proposed in merge request 1046 to improve error handling.

## Affected products

- Redox OS relibc commit 61f42d6b93adc552a9e8b6f207fca907e8ca8be2

## Timeline

- 2026-02-27: patched: Merge request 1046 submitted to fix the issue
- 2026-06-26: disclosed: CVE published

## References

- [https://github.com/Marsman1996/pocs/tree/master/redox/CVE-2026-38641](https://github.com/Marsman1996/pocs/tree/master/redox/CVE-2026-38641)
- [https://gitlab.redox-os.org/redox-os/relibc/-/issues/263](https://gitlab.redox-os.org/redox-os/relibc/-/issues/263)
- [https://gitlab.redox-os.org/redox-os/relibc/-/merge_requests/1046](https://gitlab.redox-os.org/redox-os/relibc/-/merge_requests/1046)
- [https://gitlab.redox-os.org/redox-os/relibc/-/work_items/263](https://gitlab.redox-os.org/redox-os/relibc/-/work_items/263)

## Related threats

- [relibc index out of bounds in with_argv](https://junglewise.ai/threats/cve-2026-38638-relibc-index-out-of-bounds-in-with-argv)
- [relibc seekdir() denial of service via invalid offset](https://junglewise.ai/threats/cve-2026-38636-relibc-seekdir-denial-of-service-via-invalid-offset)
- [Redox OS relibc Denial of Service in strptime via multibyte characters](https://junglewise.ai/threats/cve-2026-38639-redox-os-relibc-denial-of-service-in-strptime-via-multibyte)
- [Redox OS relibc Denial of Service in __assert_fail](https://junglewise.ai/threats/cve-2026-38640-redox-os-relibc-denial-of-service-in-assert-fail)
- [Redox OS relibc Denial of Service in pthread_rwlockattr_setpshared](https://junglewise.ai/threats/cve-2026-38637-redox-os-relibc-denial-of-service-in-pthread-rwlockattr)