# CVE-2026-75538: A Signed Length Overflow in Erlang/OTP's inet TCP Driver Overflows the Receive Buffer Into BEAM VM Memory From an Unauthenticated Peer

Status: published. Published: 2026-09-01. Updated: 2026-11-11.

An attacker that connects to an open Erlang TCP port that uses the inet driver with {packet,4} mode can use a signed overflow in an incorrect packet length calculation to overflow the receive buffer into the VM allocator area and beyond up to about 2 GB.

This would easily trash the allocated block's allocator metadata footer, and the next block, if any, and most likely cause the BEAM VM to crash. Utilizing this with precision enough to achieve Remote Code Execution would be extremely unfeasible.

This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, OTP 28.5.0.6, and OTP 29.0.6, corresponding to erts from 6.0 before 15.2.7.13, 16.4.0.6, and 17.0.6. Whether OTP before OTP 17.0, corresponding to erts before 6.0, is affected is unknown.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: EEF) — https://github.com/erlang/otp/commit/08e8efdba8500d2d6f54c6b1de1492b228017c9b

## Affected products and versions

- Erlang / OTP (otp): ≥ 17.0; < * (affected, otp); unaffected at 27.3.4.17; unaffected at 28.5.0.6; unaffected at 29.0.6. Source: CNA: EEF
- Erlang / OTP (erts): ≥ 6.0; < * (affected, otp); unaffected at 15.2.7.13; unaffected at 16.4.0.6; unaffected at 17.0.6. Source: CNA: EEF
- Erlang / OTP (erlang/otp): ≥ 84adefa331c4159d432d22840663c38f155cd4c1; < 08e8efdba8500d2d6f54c6b1de1492b228017c9b (affected, git); ≥ 08e8efdba8500d2d6f54c6b1de1492b228017c9b; < * (unaffected, git). Source: CNA: EEF

## Severity and prioritization

- CVSS 4.0: 8.2 (high); CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N; source: CNA: EEF

- CISA KEV: No listing in collected sources

- EPSS: 0.85% as of 2026-11-10; percentile 58.61%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-190, CWE-122

## Exploit evidence

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

## References

- https://github.com/erlang/otp/security/advisories/GHSA-8m6r-2pj2-25pm (CNA: EEF; vendor-advisory)

- https://cna.erlef.org/cves/CVE-2026-75538.html (CNA: EEF; related)

- https://osv.dev/vulnerability/EEF-CVE-2026-75538 (CNA: EEF; related)

- https://www.erlang.org/doc/system/versions.html#order-of-versions (CNA: EEF; x_version-scheme)

- https://github.com/erlang/otp/commit/08e8efdba8500d2d6f54c6b1de1492b228017c9b (CNA: EEF; patch)

## Provenance

- CNA: EEF: https://www.cve.org/CVERecord?id=CVE-2026-75538; retrieved 2026-11-11; source updated 2026-11-11

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-75538; retrieved 2026-11-11; source updated Not reported

Revision: c9713b75a9934ae4d671a7c612ce40aacd20a695372077c54735dfd13ca5dc59

Canonical: https://y2.dev/cve/CVE-2026-75538

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