CVE-2026-103099

Executive Summary

CVE-2026-103099 is a denial of service vulnerability affecting Pexip Infinity deployments prior to version 41.1. The flaw resides in the media implementation and is caused by improper input validation, allowing an unauthenticated remote attacker to trigger a software abort that terminates service availability. With a CVSS base score of 7.5 and a confirmed network-reachable, no-privilege-required attack path, any internet-exposed Pexip Infinity conferencing infrastructure is at risk until upgraded to a fixed release.

Technical Analysis

Pexip Infinity is a video conferencing and collaboration platform that handles SIP, H.323, WebRTC, and media stream processing through dedicated media nodes. The vulnerability is classified under CWE-617 (Reachable Assertion), which describes a condition where an application reaches an assertion or abort path that should have been unreachable under normal, validated input conditions.

The NVD description states that the issue is "improper input validation in the media implementation" that "allows a remote attacker to trigger a software abort." This tells us two important things about the mechanism:

1. Attack surface — media plane: The flaw is not in an administrative interface, web login, or configuration API. It is in the media handling subsystem — the component responsible for negotiating, receiving, parsing, and processing media streams (audio/video signaling and RTP-style traffic). This is significant because media endpoints are frequently exposed to untrusted networks to support conferencing connectivity, and they often process data from unauthenticated or minimally authenticated peers.

2. Failure mode — abort, not memory corruption: The result is a software abort. In C-family implementations, this typically corresponds to an assertion failure (assert()), a deliberate fatal-exit path, or a guard clause that terminates the process when an invariant is violated. This distinguishes CVE-2026-103099 from memory-safety classes (e.g., CWE-787 out-of-bounds write) — the flaw is one of insufficient validation leading to an unreachable-but-reachable abort condition, rather than exploitation for code execution. The integrity and confidentiality sub-scores are therefore scored None (C:N/I:N), consistent with a pure availability impact.

Because the media implementation processes externally supplied input, an attacker who can deliver crafted media or signaling data to the affected service can cause the input to fail validation checks and drive the process into its abort routine, terminating the media service. The specific parsing routine, protocol field, or message type involved is not disclosed in the available description; the exact trigger is therefore known only at the vulnerability-class level (malformed media input reaching an unvalidated code path that aborts).

At the time of writing, no public proof-of-concept, no exploit code, and no Nuclei template exist for this CVE. There is no evidence of exploitation in the wild, and CISA has not added it to the KEV catalog. The vulnerability's relative simplicity (a remote, unauthenticated single-input DoS) nonetheless makes it an attractive target for opportunistic scanning once technical details become public.

Exploitation Scenarios

No public PoC is available; the following attack chain is inferred from the vulnerability class (CWE-617, remote unauthenticated DoS via improper input validation in a media implementation). Where the source data does not specify implementation details, the attack is described at the vulnerability-class level only.

1. Reconnaissance / target identification. An attacker identifies exposed Pexip Infinity infrastructure. Because media services must accept connections from conferencing peers, the relevant media endpoints are commonly reachable from untrusted networks — including the public internet in organizations that allow external participants. Attackers enumerate candidate hosts using standard service discovery (Shodan/Censys queries for Pexip-branded services and telephony/media ports) rather than exploiting any vulnerability-specific fingerprint.

2. Triggering the flaw class. The attacker sends crafted media or signaling input to the exposed media endpoint. Improper input validation means the input contains values, structures, or fields the media implementation does not correctly validate. Under conditions the description characterizes generically — malformed or unexpected input reaching an unchecked path — the process reaches an abort condition.

3. Payload / execution method. At the vulnerability-class level, the "payload" is the malformed media/signaling message itself, delivered over the network to the media port. No authentication is required (PR:N) and no user interaction is needed (UI:N), so the attacker can deliver the triggering input directly. The described outcome is a single software abort per crafted input — a low-complexity attack (AC:L) against a network-reachable service (AV:N).

4. Post-exploitation impact. The immediate effect is termination of the affected media service process — a denial of service. Depending on deployment architecture and process supervision, this may range from a transient gap in service for impacted calls to repeated crashes if the attacker continuously re-sends the triggering input. Because the scoring assigns no confidentiality or integrity impact, no data exposure or tampering is expected from this specific flaw; the harm is availability loss for conferencing/media services.

The technical trigger details (protocol field, exact message structure) are not disclosed publicly. Until a patch is applied or a vendor advisory with specifics is published, defenders should treat any malformed-input-induced crash in Pexip Infinity media services as a potential exploitation attempt for this CVE.

Impact Assessment

The CVSS v3.1 base score is 7.5 (High), vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Decomposed:

• AV:N (Network): exploitable remotely over the network, no local access needed.
• AC:L (Low): no special conditions, race windows, or complex preconditions are required per the score.
• PR:N (None): no authentication or prior privileges required.
• UI:N (None): no victim user action required.
• S:U (Unchanged): impact is confined to the vulnerable component's security scope.
• C:N / I:N: no confidentiality or integrity impact — this is not a data-disclosure or tampering flaw.
• A:H (High): total loss of availability of the affected service.

Business impact. Pexip Infinity underpins enterprise video conferencing, telehealth, distance learning, and government/critical-communications bridging. A successful DoS can interrupt live conferences, drop scheduled meetings, and sever bridging between SIP/H.323/WebRTC participants. For organizations where conferencing is a business-critical or safety-critical service (healthcare, public safety, judicial proceedings), even brief outages carry outsized operational cost.

Blast radius. The affected component is the media implementation of Pexip Infinity prior to 41.1. The blast radius depends on how many media nodes are exposed and how the deployment is supervised: a single recurred crash affects only that node's in-progress sessions, whereas automated re-exploitation can sustain an outage across the environment. Because the attack requires no credentials, any internet-facing or partner-facing media endpoint is a candidate target.

Exploitability context. EPSS has not yet scored this CVE; no PoC, exploit, or Nuclei template exists publicly, and it is not in CISA KEV. Current real-world risk is therefore driven by opportunistic scanning potential rather than confirmed active exploitation. The absence of public exploit code should be treated as temporary — the attack is simple enough that weaponization is likely once details circulate.

Detection Guidance

Sigma Rule

title: Potential Pexip Infinity Media DoS via Improper Input Validation (CVE-2026-103099)
id: 8f3c1a20-7d64-4b2e-9c11-pexip103099
status: experimental
description: Detects abnormal process termination/abort events in Pexip Infinity media services that may indicate exploitation of CVE-2026-103099.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-103099
author: valtersit.com
date: 2026-01-01
logsource:
  product: linux
  service: syslog
detection:
  selection_process:
    process|contains:
      - 'pexip'
      - 'media'
  selection_abort:
    message|contains:
      - 'abort'
      - 'assert'
      - 'core dumped'
      - 'SIGABRT'
  condition: selection_process and selection_abort
falsepositives:
  - Legitimate service restarts or planned maintenance
  - Unrelated crashes from other software on shared hosts
level: medium
tags:
  - attack.t1499
  - cve.2026.103099

YARA Rule

rule CVE_2026_103099_Pexip_Infinity_Media_Abort
{
    meta:
        description = "Detects Pexip Infinity media component binaries potentially vulnerable to CVE-2026-103099 (improper input validation leading to software abort)"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-103099"
        date = "2026-01-01"
        severity = "high"

    strings:
        $p1 = "Pexip Infinity" ascii wide nocase
        $p2 = "pexip" ascii nocase
        $abort1 = "assert" ascii
        $abort2 = "__assert_fail" ascii
        $abort3 = "abort" ascii
        $media1 = "media" ascii nocase

    condition:
        uint32(0) == 0x464c457f and
        $p1 and
        any of ($abort*) and
        $media1 and
        filesize < 200MB
}

Suricata IDS Rule

alert udp any any -> any any (msg:"CVE-2026-103099 Pexip Infinity media malformed input possible DoS attempt"; flow:to_server; dsize:>0; content:"Pexip"; nocase; threshold: type both, track by_src, count 20, seconds 10; classtype:attempted-dos; reference:cve,2026-103099; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-103099; sid:2026103099; rev:1;)

Note: Because the exact media protocol/message structure is not publicly disclosed, this rule targets anomalous high-volume media traffic to Pexip-branded endpoints as a heuristic for attempted abuse. It is not a precise signature for the trigger input and should be tuned to the deployment's protocol and port layout.

Elastic Detection

sequence by host.id, process.pid with maxspan=30s
  [process where process.name : "*media*" and event.action == "start"]
  [process where process.name : "*media*" and event.action in ("end", "stop")]

Complementary query for crash signatures:

process where event.type == "end" and process.name : "*pexip*" and
  (process.exit_code == 134 or process.exit_code == 139)

Note: Exit code 134 corresponds to SIGABRT (abort) on Linux, aligning with the "software abort" behavior described for CVE-2026-103099. Correlate with incoming media connection volume to identify deliberate triggering.

Splunk SPL Query

index=infra (process_name="*pexip*" OR process_name="*media*")
| search ("abort" OR "assert" OR "SIGABRT" OR "core dumped")
| stats count min(_time) as first_seen max(_time) as last_seen by host, process_name, src
| where count > 3
| sort - count

For network-side triage, correlate repeated connection spikes to exposed media endpoints:

index=network dest_port IN (1720, 5060, 3478, 50000-60000)
| stats count by src, dest_ip, dest_port
| where count > 100
| sort - count

Wazuh OSSEC Rule

<group name="pexip,cve-2026-103099,denial_of_service,">
  <rule id="103099" level="10">
    <if_sid>530</if_sid>
    <match>pexip|media</match>
    <description>CVE-2026-103099: Pexip Infinity media service abort/crash detected - possible DoS exploitation attempt.</description>
    <group>attack.t1499,</group>
  </rule>

  <rule id="103100" level="12">
    <if_sid>103099</if_sid>
    <match>abort|assert|core dumped|SIGABRT</match>
    <description>CVE-2026-103099: Confirmed Pexip Infinity software abort in media process - likely malicious trigger.</description>
    <group>attack.t1499,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor advisory, patch reference, or workaround was available in the tracked intelligence. The fix version is inferred from the NVD description ("Pexip Infinity before 41.1"), which implies the remediation is the 41.1 release, but this has not been independently confirmed by a vendor advisory source.

1. Immediate mitigations

   • Restrict network access to media services to only the trusted networks and peers that legitimately require conferencing connectivity. Eliminate unnecessary internet exposure of media endpoints where operationally feasible.
   • Front media endpoints with a reverse proxy, SBC, or firewall ACL that enforces allowlisting and rate limiting so unauthenticated, malformed traffic is filtered before reaching the media implementation.
   • Enable process supervision/auto-restart with alerting (systemd, container restart policies) so aborts are immediately logged and recovered, and deploy the detection rules above to catch repeated triggering.
   • Monitor for crash/abort events (SIGABRT, exit code 134) in media processes and treat repeated occurrences as an active exploitation attempt.
   • Because no vendor workaround is published, do not assume application-level configuration can neutralize the flaw; network controls are the primary interim defense.

2. Patch / upgrade steps

   • Upgrade Pexip Infinity to version 41.1 or later as soon as a vendor-confirmed release is available. Validate the fix against Pexip's official security advisory and release notes before relying on the version boundary from NVD alone.
   • If 41.1 is not yet deployed, treat the environment as exposed and prioritize based on internet egress of media services.
   • After upgrading, verify the media implementation version and confirm no legacy media nodes remain on unsupported builds.

3. Long-term hardening

   • Adopt a patch-management SLA for real-time communications infrastructure, which is high-exposure by nature.
   • Segment conferencing/media infrastructure from general corporate networks and apply least-privilege network policy.
   • Deploy fuzzing and input-validation hardening reviews for media-plane components during procurement and security assessment.
   • Maintain continuous vulnerability monitoring for Pexip Infinity releases and subscribe to the vendor's security advisories to obtain authoritative patch details not yet present in public feeds.
   • Track CISA KEV and EPSS for this CVE; escalate priority immediately if proof-of-concept code or in-the-wild exploitation appears.

References

• NVD — CVE-2026-103099: https://nvd.nist.gov/vuln/detail/CVE-2026-103099
• CWE-617 (Reachable Assertion): https://cwe.mitre.org/data/definitions/617.html
• Pexip Infinity documentation and release/security advisories: https://docs.pexip.com/ (consult vendor for the confirmed 41.1 advisory)
• CISA Known Exploited Vulnerabilities Catalog (entry not present at time of writing): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• FIRST EPSS (not yet scored at time of writing): https://www.first.org/epss/

No threat actor campaigns or exploit-in-the-wild evidence are associated with CVE-2026-103099 in the available data. No public PoC, exploit code, or Nuclei template exists. This report will require revision once a vendor security advisory or public exploit detail is released.