# CVE-2026-123805: SIPSorcery: Unbounded SCTP SACK gap/duplicate counts cause out-of-bounds read that kills the data-channel receive thread (DoS)

Status: published. Published: 2026-11-09. Updated: 2026-11-12.

SIPSorcery is a WebRTC, SIP, and VoIP library for C# and .NET. Prior to 10.0.14, SctpSackChunk.ParseChunk reads the numGapAckBlocks and numDuplicateTSNs fields from an attacker-controlled SCTP SACK chunk without checking that the corresponding entries fit the declared chunk length. A negotiated WebRTC peer can send a checksum-valid malformed SACK chunk that drives the parser beyond the 262144-byte receive buffer. The resulting IndexOutOfRangeException bypasses the recoverable ApplicationException handler in RTCSctpTransport.DoReceive, causing the generic handler to exit the dedicated receive loop and permanently terminate the SCTP association and all data channels. This issue is fixed in 10.0.14.

## Remediation

- fix: SIPSorcery (nuget): GitHub reports patched versions 10.0.14. Check the advisory for the affected release branch. (source: GitHub GHSA-jwjp-4649-v8jp) — https://github.com/sipsorcery-org/sipsorcery/security/advisories/GHSA-jwjp-4649-v8jp
- fix: SIPSorcery (NuGet): OSV reports a fixed version 10.0.14. Check the advisory for supported release branches. (source: OSV GHSA-jwjp-4649-v8jp) — https://github.com/advisories/GHSA-jwjp-4649-v8jp

## Affected products and versions

- sipsorcery-org / sipsorcery: < 10.0.14 (affected). Source: CNA: GitHub_M
-  / SIPSorcery (SIPSorcery): <= 10.0.13 (affected, GitHub advisory range). Source: GitHub GHSA-jwjp-4649-v8jp
-  / SIPSorcery (SIPSorcery): 1.3.0-PRE (affected, NuGet); 1.3.1 (affected, NuGet); 1.4.0 (affected, NuGet); 1.4.1 (affected, NuGet); 1.5.0 (affected, NuGet); 1.5.2 (affected, NuGet); 1.5.3 (affected, NuGet); 1.5.5 (affected, NuGet); 1.5.6 (affected, NuGet); 1.6.0 (affected, NuGet); 1.6.1 (affected, NuGet); 1.6.2 (affected, NuGet); 10.0.1 (affected, NuGet); 10.0.10 (affected, NuGet); 10.0.11 (affected, NuGet); 10.0.12 (affected, NuGet); 10.0.13 (affected, NuGet); 10.0.2 (affected, NuGet); 10.0.3 (affected, NuGet); 10.0.4-pre (affected, NuGet); 10.0.5 (affected, NuGet); 10.0.6 (affected, NuGet); 10.0.7 (affected, NuGet); 10.0.8 (affected, NuGet); 10.0.9 (affected, NuGet); 2.0.0 (affected, NuGet); 2.0.1 (affected, NuGet); 3.0.0 (affected, NuGet); 3.0.1 (affected, NuGet); 3.0.2 (affected, NuGet); 3.0.3 (affected, NuGet); 3.0.4 (affected, NuGet); 3.1.0 (affected, NuGet); 3.2.0 (affected, NuGet); 3.3.0 (affected, NuGet); 3.4.0 (affected, NuGet); 3.5.0 (affected, NuGet); 3.6.0 (affected, NuGet); 4.0.0-rc (affected, NuGet); 4.0.1-rc (affected, NuGet); 4.0.13-pre (affected, NuGet); 4.0.2-rc (affected, NuGet); 4.0.28-pre (affected, NuGet); 4.0.29-pre (affected, NuGet); 4.0.3-rc (affected, NuGet); 4.0.30-pre (affected, NuGet); 4.0.31-pre (affected, NuGet); 4.0.32-pre (affected, NuGet); 4.0.33-pre (affected, NuGet); 4.0.34-pre (affected, NuGet); 4.0.35-pre (affected, NuGet); 4.0.4-rc (affected, NuGet); 4.0.40-pre (affected, NuGet); 4.0.41-pre (affected, NuGet); 4.0.42-pre (affected, NuGet); 4.0.43-pre (affected, NuGet); 4.0.44-pre (affected, NuGet); 4.0.45-pre (affected, NuGet); 4.0.46-pre (affected, NuGet); 4.0.47-pre (affected, NuGet); 4.0.49-pre (affected, NuGet); 4.0.50-pre (affected, NuGet); 4.0.51-pre (affected, NuGet); 4.0.55-pre (affected, NuGet); 4.0.58-pre (affected, NuGet); 4.0.59-pre (affected, NuGet); 4.0.60-pre (affected, NuGet); 4.0.7-rc (affected, NuGet); 4.0.8-rc (affected, NuGet); 5.1.0 (affected, NuGet); 5.1.1 (affected, NuGet); 5.1.2 (affected, NuGet); 5.1.4-pre (affected, NuGet); 5.1.5-pre (affected, NuGet); 5.1.6-pre (affected, NuGet); 5.1.7-pre (affected, NuGet); 5.1.8-pre (affected, NuGet); 5.2.0 (affected, NuGet); 5.2.3 (affected, NuGet); 5.3.0-pre (affected, NuGet); 5.3.3-pre (affected, NuGet); 6.0.1-pre (affected, NuGet); 6.0.11 (affected, NuGet); 6.0.12 (affected, NuGet); 6.0.2 (affected, NuGet); 6.0.3 (affected, NuGet); 6.0.4 (affected, NuGet); 6.0.6 (affected, NuGet); 6.0.7 (affected, NuGet); 6.0.8 (affected, NuGet); 6.0.9 (affected, NuGet); 6.1.0-pre (affected, NuGet); 6.1.1-pre (affected, NuGet); 6.2.0 (affected, NuGet); 6.2.1 (affected, NuGet); 6.2.3 (affected, NuGet); 6.2.4 (affected, NuGet); 8.0.0 (affected, NuGet); 8.0.1 (affected, NuGet); 8.0.10 (affected, NuGet); 8.0.11 (affected, NuGet); 8.0.12 (affected, NuGet); 8.0.13 (affected, NuGet); 8.0.14 (affected, NuGet); 8.0.15-pre (affected, NuGet); 8.0.20-pre (affected, NuGet); 8.0.21-pre (affected, NuGet); 8.0.22 (affected, NuGet); 8.0.23 (affected, NuGet); 8.0.3 (affected, NuGet); 8.0.4 (affected, NuGet); 8.0.5 (affected, NuGet); 8.0.6 (affected, NuGet); 8.0.7 (affected, NuGet); 8.0.9 (affected, NuGet); Ecosystem version events: introduced 0; fixed 10.0.14. Source: OSV GHSA-jwjp-4649-v8jp

## Severity and prioritization

- 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: GitHub_M

- 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: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.37% as of 2026-11-12; percentile 31.60%

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

- Weaknesses: CWE-125, CWE-755

## Exploit evidence

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

## References

- https://github.com/sipsorcery-org/sipsorcery/security/advisories/GHSA-jwjp-4649-v8jp (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/sipsorcery-org/sipsorcery/pull/1772 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sipsorcery-org/sipsorcery/commit/a2466550bb2a28821c73fb1961bc33dcc467f8cf (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sipsorcery-org/sipsorcery/commit/a2466550bb2a28821c73fb1961bc33dcc467f8cf (security-advisories@github.com)

- https://github.com/sipsorcery-org/sipsorcery/pull/1772 (security-advisories@github.com)

- https://github.com/sipsorcery-org/sipsorcery/security/advisories/GHSA-jwjp-4649-v8jp (security-advisories@github.com)

- https://github.com/sipsorcery-org/sipsorcery/security/advisories/GHSA-jwjp-4649-v8jp (GitHub Security Advisories; advisory)

- https://github.com/advisories/GHSA-jwjp-4649-v8jp (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-jwjp-4649-v8jp (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-123805; retrieved 2026-11-12; source updated 2026-11-12

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123805; retrieved 2026-11-10; source updated 2026-11-09

- GitHub Security Advisories: https://github.com/sipsorcery-org/sipsorcery/security/advisories/GHSA-jwjp-4649-v8jp; retrieved 2026-11-12; source updated 2026-11-09

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-jwjp-4649-v8jp; retrieved 2026-11-12; source updated 2026-11-09

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-123805; retrieved 2026-11-12; source updated Not reported

Revision: 2673a7deceaa15c565c8449fe7e37e547bfd28f65e02b71b73ec317ac46f3314

Canonical: https://y2.dev/cve/CVE-2026-123805

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.