# CVE-2026-104074: Coturn 4.10.0 Uninitialized Stack Memory Disclosure via ERROR-CODE

Status: published. Published: 2026-10-07. Updated: 2026-11-08.

Coturn 4.10.0 contains an uninitialized memory disclosure vulnerability that allows remote unauthenticated attackers to leak stack memory contents by sending a TURN Allocate request without credentials. Attackers can exploit the stun_init_error_response_common_str() function in src/client/ns_turn_msg.c, which fails to zero-initialize the avalue buffer before computing its length with strlen() and copying leaked stack bytes into the ERROR-CODE reason phrase, exposing pointer fragments that weaken ASLR and enable precise version fingerprinting.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/coturn/coturn/pull/1878
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/coturn/coturn/commit/741b2983cc52f967dd08c438fd72a5f08f13ca27

## Affected products and versions

- coturn / coturn (coturn/coturn): ≥ 4.10.0; < 4.11.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 6.9 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.31% as of 2026-11-08; percentile 24.13%

- SSVC: exploitation none; automatable yes; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-908

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/coturn/coturn/releases/tag/4.11.0 (CNA: VulnCheck; release-notes)

- https://github.com/coturn/coturn/pull/1878 (CNA: VulnCheck; issue-tracking, patch)

- https://github.com/coturn/coturn/commit/741b2983cc52f967dd08c438fd72a5f08f13ca27 (CNA: VulnCheck; patch)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-104074; retrieved 2026-11-08; source updated 2026-11-08

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-104074; retrieved 2026-11-08; source updated Not reported

Revision: e3e295516427b4b2f49f2d70183eca0e244b1e19aa6f8e92fdcd9e2e8a10d424

Canonical: https://y2.dev/cve/CVE-2026-104074

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