SIPSorcery vulnerable to Denial of Service via out-of-bounds read in SCTP SACK chunk parsing

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary SctpSackChunk.ParseChunk reads the numGapAckBlocks and numDuplicateTSNs fields (each up to 65535) directly from an attacker-controlled SCTP SACK chunk and loops that many times reading 4 bytes per iteration, with no validation of the counts against the chunk length or the receive buffer. A single crafted SACK chunk from a negotiated WebRTC peer forces reads past the end of the 262144-byte receive buffer, raising IndexOutOfRangeException, which is not caught by the recoverable handler and terminates the dedicated SCTP receive thread — permanently killing the SCTP association and all data channels. Root Cause src/SIPSorcery/net/SCTP/Chunks/SctpSackChunk.cs: - ushort numGapAckBlocks = NetConvert.ParseUInt16(buffer, startPosn + 8); (:141) - ushort numDuplicateTSNs = NetConvert.ParseUInt16(buffer, startPosn + 10); (:142) - gap-ack loop (:146) and duplicate-TSN loop (:154) index the buffer via NetConvert.ParseUInt16/32 (buffer[posn], no bounds check — sys/Net/NetConvert.cs:30,41).…

Published by the source

12 Aug 2026, 19:30 UTC

Last modified by the source

12 Aug 2026, 19:45 UTC

Source last checked

26 Oct 2026, 17:05 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-jwjp-4649-v8jp

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-jwjp-4649-v8jp

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# Patch Next advisory brief: GHSA-jwjp-4649-v8jp

Advisory: SIPSorcery vulnerable to Denial of Service via out-of-bounds read in SCTP SACK chunk parsing
IDs: GHSA-jwjp-4649-v8jp
Record: https://patchnext.com/advisories/ghsa-jwjp-4649-v8jp (revision 2, source checked 26 Oct 2026, 17:05 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: sipsorcery 10.0.14. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet sipsorcery: affected <= 10.0.13; fixed in 10.0.14

## Suggested inspection (read-only)
- NuGet sipsorcery: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on sipsorcery.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-jwjp-4649-v8jp (OSV record GHSA-jwjp-4649-v8jp lists affected ranges: NuGet sipsorcery >=0 <10.0.14 (fixed))
- Verified: https://github.com/advisories/GHSA-jwjp-4649-v8jp (GitHub-reviewed advisory GHSA-jwjp-4649-v8jp lists affected ranges: NuGet sipsorcery >=0 <=10.0.13)

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