# CVE-2026-123200: VRPN through 07.36 Out-of-bounds Write via SENDER_DESCRIPTION/TYPE_DESCRIPTION length index

Status: published. Published: 2026-11-05. Updated: 2026-11-09.

VRPN through 07.36 contains an out-of-bounds stack write vulnerability in vrpn_Endpoint::handle_sender_message() and handle_type_message() that allows unauthenticated remote peers to write outside a stack buffer via an unchecked length index. Attackers can connect, complete the version-cookie exchange, and send a SENDER_DESCRIPTION or TYPE_DESCRIPTION message with an out-of-range or negative index to crash the process.

## 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/vrpn/vrpn/commit/0da5b0b71e06e8c318a4e674c84caee12251a782
- 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/vrpn/vrpn/commit/c893b583d928fd17d756b39271b2eae71766e7f2

## Affected products and versions

- VRPN / VRPN (vrpn/vrpn): ≥ 0; ≤ 07.36 (affected, custom). 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

- 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- 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: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.45% as of 2026-11-09; percentile 39.07%

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

- Weaknesses: CWE-129

## Exploit evidence

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

## References

- https://github.com/vrpn/vrpn/commit/0da5b0b71e06e8c318a4e674c84caee12251a782 (CNA: VulnCheck; patch)

- https://github.com/vrpn/vrpn/commit/c893b583d928fd17d756b39271b2eae71766e7f2 (CNA: VulnCheck; patch)

- https://github.com/vrpn/vrpn/blob/79deb000cc0b47ae49a80c92c78167c02d8a04d8/vrpn_Connection.C#L4554 (CNA: VulnCheck; technical-description)

- https://github.com/vrpn/vrpn/blob/79deb000cc0b47ae49a80c92c78167c02d8a04d8/vrpn_Connection.C#L4482 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/vrpn-through-07.36-out-of-bounds-write-via-sender-description-type-description-length-index (CNA: VulnCheck; third-party-advisory)

- https://github.com/vrpn/vrpn/blob/79deb000cc0b47ae49a80c92c78167c02d8a04d8/vrpn_Connection.C#L4482 (disclosure@vulncheck.com)

- https://github.com/vrpn/vrpn/blob/79deb000cc0b47ae49a80c92c78167c02d8a04d8/vrpn_Connection.C#L4554 (disclosure@vulncheck.com)

- https://github.com/vrpn/vrpn/commit/0da5b0b71e06e8c318a4e674c84caee12251a782 (disclosure@vulncheck.com)

- https://github.com/vrpn/vrpn/commit/c893b583d928fd17d756b39271b2eae71766e7f2 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/vrpn-through-07.36-out-of-bounds-write-via-sender-description-type-description-length-index (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-123200; retrieved 2026-11-09; source updated 2026-11-09

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123200; retrieved 2026-11-06; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-123200; retrieved 2026-11-09; source updated Not reported

Revision: ee7804f78a9cae945f3db50c0bce3cd5d6040fbed64973443bba645bfa13d28d

Canonical: https://y2.dev/cve/CVE-2026-123200

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