CVE-2026-103109

Executive Summary

CVE-2026-103109 is an improper input validation vulnerability (CWE-787, out-of-bounds write) in the media implementation of Pexip Infinity, a widely deployed enterprise video conferencing and collaboration platform. A remote, unauthenticated attacker who can deliver a crafted media stream to an exposed Pexip Infinity service can trigger memory corruption or a controlled software abort, resulting in denial of service, with the potential for further memory-corruption impact. The vulnerability is rated CVSS 7.7 (High) and affects all Pexip Infinity versions before 38.2, as well as the 39.0, 39.1, and 40.0 releases.

Technical Analysis

Pexip Infinity is a software-based conferencing and media routing platform that processes real-time media streams (audio and video) received over standard conferencing protocols. The CVE describes "improper input validation in the media implementation" — that is, the component responsible for parsing and processing inbound media streams. According to the NVD description, a crafted media stream may cause a malformed processing condition that results in either a "controlled abort" or "memory corruption."

The assigned CWE-787 (Out-of-bounds Write) indicates that the root cause is a memory-safety defect: input data from a media stream is used without adequate validation of length, structure, or boundary, causing data to be written past the boundaries of an allocated buffer. The phrase "controlled abort during processing" suggests the malformed input frequently produces a deterministic crash (an abort), which is the reliable, low-effort outcome. The description explicitly notes "has the potential to achieve memory corruption," meaning the same input validation failure could — under a carefully crafted stream — lead to corruption of adjacent memory rather than a clean abort. That distinction is what elevates this from a simple crash to a potentially serious memory-corruption issue.

The CVSS vector reveals the important characteristics of this flaw:

• Attack Vector: Network (AV:N) — the attacker does not need local access; media is delivered remotely.
• Attack Complexity: High (AC:H) — the description supports this: "a crafted media stream" must be constructed with sufficient precision to reach the vulnerable processing path, and the "controlled abort" vs. "memory corruption" outcomes depend on exact input shaping.
• Privileges Required: None (PR:N) and User Interaction: None (UI:N) — no authentication or victim interaction is needed; the service processes inbound media autonomously.
• Scope: Unchanged (S:U) — the impact remains within the vulnerable component.
• Impact: Low Confidentiality (C:L), High Integrity (I:H), High Availability (A:H) — consistent with memory corruption that can overwrite state (integrity), crash the process (availability), and potentially leak limited data.

The attack surface is the media-handling interface of Pexip Infinity. Because the platform is designed to accept and process media from conferencing endpoints, this interface is intentionally reachable from the network. No authentication is required to reach the media processing logic, so any host able to send traffic to the exposed media service is a potential source of exploitation attempts. No public proof-of-concept or exploit code exists at the time of writing, and no Nuclei template is available. The exact vulnerable function, buffer, and parsing routine are not disclosed in the NVD description, so the analysis is necessarily at the vulnerability-class level.

Exploitation Scenarios

No public PoC is available; the attack chain below is inferred from the vulnerability class (CWE-787) and the NVD description.

1. Reconnaissance / target identification. An attacker enumerates internet-facing Pexip Infinity deployments using search engines (Shodan/Censys) for the product's media/conferencing services and exposed ports. Version identification is attempted through banners, TLS certificate subject names, or HTTP response headers to determine whether the target runs a version before 38.2 or in the 39.0/39.1/40.0 range.

2. Triggering the flaw. The attacker establishes a session capable of delivering media to the target's media implementation and crafts a malformed media stream. The crafted input is designed to reach the media-parsing/processing path in a state the code does not validate, exploiting the improper input validation described in the advisory. No authentication is required (PR:N) and no victim interaction is needed (UI:N).

3. Payload/execution at the class level. Because this is CWE-787, the crafted stream supplies data whose length or structure is not validated by the media implementation. Depending on the exact input, the processing path either writes beyond an in-bounds buffer and aborts — a denial-of-service condition — or corrupts adjacent memory, which could enable further impact. The high attack complexity (AC:H) reflects that reliable memory-corruption exploitation requires precise stream construction; a basic malformed stream is far more likely to produce the controlled abort and crash.

4. Post-exploitation impact. The guaranteed outcome is availability loss: the media service/process aborts, disrupting conferences and hosted meetings (A:H). Integrity impact (I:H) reflects possible corruption of in-process state. Any confidentiality impact (C:L) would be limited/incidental. There is no evidence of exploitation in the wild for this CVE at the time of writing, and no CISA KEV listing.

Impact Assessment

A successful exploitation attempt against a vulnerable Pexip Infinity deployment causes a denial-of-service condition by crashing the media processing component, directly disrupting ongoing conferences and hosted video meetings. Given the AV:N/PR:N/UI:N combination, any internet- or network-exposed Pexip media service is in scope — including customer-facing collaboration portals and internal enterprise conferencing infrastructure. Because the target is a real-time communication platform, even a brief outage affects all participants in active sessions, and repeated attempts can produce sustained unavailability.

The CVSS score of 7.7 (High) is driven primarily by the availability (A:H) and integrity (I:H) impacts. Integrity impact implies that corruption of in-process memory or state may produce incorrect behavior beyond a simple crash. Confidentiality impact is Low (C:L), suggesting limited or incidental data exposure rather than systematic extraction. Scope is Unchanged (S:U), meaning the blast radius is contained within the Pexip component rather than pivoting automatically to the host environment. However, if the media process runs with elevated privileges or shares resources with adjacent services, the practical blast radius could extend further — this depends on deployment architecture not specified in the advisory.

Organizations running Pexip Infinity for regulated communications, remote hearings, telehealth, or customer support should treat this as a high-priority availability risk.

Detection Guidance

Sigma Rule

title: Pexip Infinity Media Processing Abort - Potential CVE-2026-103109 Exploitation
id: 8f2b6c1e-4a3d-4c9e-9b21-7d5f0c9a1e33
status: experimental
description: Detects abnormal termination/abort of the Pexip Infinity media process, consistent with malformed media handling described in CVE-2026-103109.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-103109
author: valtersit.com
date: 2026/01/01
logsource:
  product: linux
  service: syslog
detection:
  selection_process:
    - message|contains: 'pexip'
    - message|contains: 'media'
  selection_crash:
    - message|contains: 'abort'
    - message|contains: 'segfault'
    - message|contains: 'core dumped'
    - message|contains: 'signal 6'
    - message|contains: 'signal 11'
  condition: selection_process and selection_crash
falsepositives:
  - Legitimate media process restarts during maintenance
  - Kernel OOM-killer termination unrelated to media input
level: medium

YARA Rule

rule CVE_2026_103109_Pexip_Media_MemoryCorruption
{
    meta:
        description = "Heuristic detection of memory-corruption indicators in Pexip Infinity media components (CVE-2026-103109); monitor/adjust for environment"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-103109"
        date = "2026-01-01"
        severity = "high"

    strings:
        $pexip = "Pexip" ascii wide nocase

    condition:
        $pexip and filesize < 20MB
}

Suricata IDS Rule

alert udp any any -> any any (msg:"CVE-2026-103109 Pexip Infinity media stream anomaly - potential DoS attempt"; flow:stateless; dsize:>1200; threshold: type both, track by_src, count 50, seconds 10; classtype:attempted-dos; reference:cve,2026-103109; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-103109; sid:2026103109; rev:1;)

Elastic Detection

process where event.type == "end" and process.name in ("pexip", "pexip-media", "media")
  and process.exit_code != 0
  and (
    process.exit_code == 134 or
    process.exit_code == 139 or
    process.signaled == true
  )

Splunk SPL Query

index=os sourcetype=syslog (pexip OR media)
| search ("abort" OR "segfault" OR "signal 6" OR "signal 11" OR "core dumped")
| stats count values(message) as messages by host, process
| where count > 0
| sort - count

Wazuh OSSEC Rule

<group name="pexip,cve-2026-103109,">
  <rule id="202610910" level="8">
    <decoded_as>syslog</decoded_as>
    <match>pexip|media</match>
    <regex>abort|segfault|signal 6|signal 11|core dumped</regex>
    <description>Pexip Infinity media process abort/crash - possible CVE-2026-103109 denial of service attempt</description>
    <mitre>
      <id>T1499</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source).

1. Immediate mitigations. Until a fixed release is deployable, restrict network access to Pexip Infinity media/conferencing services to trusted source networks and known conferencing endpoints. Deploy firewall and/or IDS/IPS controls in front of the media interfaces. Enable high-availability/failover so that a media-process abort on one node does not fully interrupt service. Ensure the media process runs with least privilege and under a supervisor that logs and captures core dumps for forensic review.

2. Patch/upgrade steps. The advisory states the vulnerability affects Pexip Infinity before 38.2, plus 39.0, 39.1 and 40.0. No vendor patch has been confirmed by tracked sources (patch confidence 0/4), and the NVD description references the fixed baseline as 38.2. Verify the current fixed version directly with the vendor advisory before upgrading, then move deployments off affected versions (pre-38.2, 39.0, 39.1, 40.0) to the vendor-designated fixed release. Test in a staging environment and schedule upgrades during a maintenance window.

3. Long-term hardening. Enforce strict input validation and fuzz testing across media-parsing code paths in custom or integrated components. Segment real-time media infrastructure from general corporate networks. Apply vendor security advisories promptly, maintain an inventory of Pexip Infinity instances with accurate version tracking, and monitor for anomalous media traffic volume and abnormal process terminations as early indicators.

References

• NVD — CVE-2026-103109: https://nvd.nist.gov/vuln/detail/CVE-2026-103109
• Pexip Security Advisories (vendor): https://www.pexip.com/security
• MITRE ATT&CK T1499 — Endpoint Denial of Service: https://attack.mitre.org/techniques/T1499/
• CWE-787 — Out-of-bounds Write: https://cwe.mitre.org/data/definitions/787.html
• CISA Known Exploited Vulnerabilities Catalog (not currently listed): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

No public proof-of-concept, exploit code, or Nuclei template is available for this CVE. No evidence of exploit-in-the-wild activity or associated threat actor campaigns has been identified at the time of writing, and the CVE is not listed in CISA KEV.