# CVE-2026-116543: Open5GS 1.3.0 through 2.8.0 Heap Out-of-Bounds Write via SBI Multipart Parser

Status: published. Published: 2026-10-26. Updated: 2026-11-02.

Open5GS 1.3.0 through 2.8.0 contains a heap out-of-bounds write vulnerability in parse_multipart() that allows unauthenticated attackers to corrupt memory by supplying an empty multipart boundary. Attackers can send a single crafted multipart/related request to the SBI interface of any network function, overflowing the lookbehind buffer and crashing it.

## 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/open5gs/open5gs/commit/6820c2743b5b5e126e3755d2f92dae2b236732df

## Affected products and versions

- open5gs / open5gs: ≥ 1.3.0; ≤ 2.8.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.39% as of 2026-11-02; percentile 32.77%

- SSVC: exploitation poc; automatable yes; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-787

## Exploit evidence

- exploit: https://github.com/open5gs/open5gs/security/advisories/GHSA-25v2-v588-jq8g (ADP: CISA-ADP)

## References

- https://github.com/open5gs/open5gs/security/advisories/GHSA-25v2-v588-jq8g (CNA: VulnCheck; vendor-advisory)

- https://github.com/open5gs/open5gs/commit/6820c2743b5b5e126e3755d2f92dae2b236732df (CNA: VulnCheck; patch)

- https://github.com/open5gs/open5gs/blob/v2.8.0/lib/sbi/message.c#L3372 (CNA: VulnCheck; technical-description)

- https://github.com/open5gs/open5gs/blob/v2.8.0/lib/sbi/contrib/multipart_parser.c#L260 (CNA: VulnCheck; technical-description)

- https://github.com/open5gs/open5gs (CNA: VulnCheck; product)

- https://www.vulncheck.com/advisories/open5gs-1.3.0-through-2.8.0-heap-out-of-bounds-write-via-sbi-multipart-parser (CNA: VulnCheck; third-party-advisory)

- https://github.com/open5gs/open5gs/security/advisories/GHSA-25v2-v588-jq8g (ADP: CISA-ADP; exploit)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-116543; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-116543; retrieved 2026-11-02; source updated Not reported

Revision: 1ac7f46e8f3d31b6b651dc9ef20e5b28a868de5bc52dc12ff1ba056527b7f154

Canonical: https://y2.dev/cve/CVE-2026-116543

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