How severe is CVE-2026-54632?

CVE-2026-54632 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-54632?

CVE-2026-54632 affects the following packages: SIPSorcery (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2026-54632?

Update SIPSorcery to 10.0.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54632 is resolved across your whole dependency graph.

How do I detect CVE-2026-54632 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for SIPSorcery, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-54632 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-54632 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-54632 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-54632?

CVE-2026-54632 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 53th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-54632?

CVE-2026-54632 is classified as Improper Input Validation (CWE-20), CWE-755 (CWE-755). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-54632 published, and has it been updated?

CVE-2026-54632 was published on September 14, 2026 and was last updated on October 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET

.NET NuGet

Not in CISA KEV

HIGH severity

CVE-2026-54632 — SIPSorcery

HIGHFix: sipsorcery-org/sipsorcery@bdb76cb

CVE-2026-54632 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in SIPSorcery. A fix is available for SIPSorcery — see the affected versions and patch details below.

SIPSorcery: Malformed UDP packet on the RTP/ICE socket can remotely terminate a media session (DoS)

Also known asGHSA-28gm-jrmw-xx93

Published

Sep 14, 2026

Updated

Oct 2, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 13, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-54632.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs53th percentile — riskier than 53% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-54632 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 386,684 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

.NETSIPSorcery

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

Impact

A single malformed inbound UDP packet on the RTP/ICE socket can remotely terminate an active RTP or WebRTC media session. The packet receive handler indexes packet (and STUN attribute) bytes without sufficient length checks and throws, and the UDP receive loop converted any such exception into a channel Close rather than dropping the packet. One small, unauthenticated packet therefore ends the media session.

This is reachable during ICE connectivity checks — before the DTLS handshake and before any STUN MESSAGE-INTEGRITY verification. Because the RTP/ICE port is shared/advertised in the ICE candidates, a peer or on-path attacker can reach it (exposure is lower for a blind off-path attacker that must first learn the ephemeral port). Impact is availability only — no loss of confidentiality or integrity.

Affected versions

NuGet package SIPSorcery <= 10.0.8.

Patches

Fixed in 10.0.9.

Root cause

Two issues combine:

Unchecked indexing of untrusted bytes.
- RTPChannel.OnRTPPacketReceived read packet[1] after only checking the packet was non-empty, so a 1-byte packet threw IndexOutOfRangeException.
- STUNAttribute.ParseMessageAttributes passed a null/short value to the typed attribute parsers, and STUNXORAddressAttribute (and the non-XOR STUNAddressAttribute) then read attributeValue[1], AsSpan(2) and AsSpan(4) with no length check. A STUN message carrying an XOR-MAPPED-ADDRESS, XOR-PEER-ADDRESS or XOR-RELAYED-ADDRESS attribute of length 0–7 threw (NullReferenceException for length 0, IndexOutOfRangeException/ArgumentOutOfRangeException for 1–7).
The UDP receive loop closed the channel on any exception. The catch-all in UdpReceiver.EndReceiveFrom called Close(), tearing down the channel, instead of dropping the offending packet and continuing. This was systemic: any unhandled exception anywhere in the packet pipeline (STUN, RTP, RTCP, DTLS demux, SRTP, TURN) became a channel teardown.

Fix

UdpReceiver.EndReceiveFrom: a non-socket exception now logs and drops the single packet and re-arms the receive loop (matching the existing SIPUDPChannel behaviour), instead of closing the channel. Genuine socket failures continue to be handled separately.
RTPChannel.OnRTPPacketReceived: requires a minimum packet length (RTPHeader.MIN_HEADER_LEN) before indexing the discriminator bytes.
STUN parsing: ParseMessageAttributes validates each attribute value length and skips malformed/truncated attributes; the XOR/address attribute constructors validate length defensively; ParseSTUNMessage no longer dereferences a null attribute list.

Regression tests were added covering the 1-byte packet (channel stays open and remains usable), short/zero-length XOR address attributes (0–7 bytes), and truncated STUN messages.

Workarounds

None within the library short of upgrading. Restricting the RTP/ICE port to known peers at the network layer reduces exposure but does not eliminate it, since a negotiating peer can still trigger the condition.

Credit

Responsibly reported by Lokhesh Ujhoodha.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`SIPSorcery`	all versions	10.0.9`dotnet add package SIPSorcery --version 10.0.9`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for SIPSorcery, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update SIPSorcery to 10.0.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54632 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Impact A single malformed inbound UDP packet on the RTP/ICE socket can remotely terminate an active RTP or WebRTC media session. The packet receive handler indexes packet (and STUN attribute) bytes without sufficient length checks and throws, and the UDP receive loop converted any such exception into a channel `Close` rather than dropping the packet. One small, unauthenticated packet therefore ends the media session. This is reachable during ICE connectivity checks — before the DTLS handshake and before any STUN `MESSAGE-INTEGRITY` verification. Because the RTP/ICE port is shared/adverti