CVE-2026-111793: Openwave Messaging Limited Webtop Media Transcoder flaw exploited in the wild, what we know

Openwave Webtop Media Transcoder does not enforce administrator-defined file type restrictions to restrict the file-types to be converted. This may allow an authenticated user to process and convert unintended document types if bypassing the Webmail experience.

• Severity: MEDIUM (CVSS 3.1 4.3, vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L).
• Weakness: CWE-669.
• NVD published 2026-10-16, status Analyzed.

Anyone running Openwave Messaging Limited Webtop Media Transcoder in the version ranges below. Internet-facing instances are the priority.

• openwave webtop media transcoder: up to (not including) 1.1.22.0.

Version ranges come from the NVD CPE configuration. Confirm against the vendor advisory before you rely on them.

• Exploited in the wild: added to the CISA Known Exploited Vulnerabilities catalog on 2026-11-10; federal remediation due date 2026-11-24.

CISA added CVE-2026-111793 to its Known Exploited Vulnerabilities catalog on 2026-11-10. A KEV listing means CISA has evidence that attackers are using the flaw against real systems, not just that it could be used.

If your business runs Openwave Messaging Limited Webtop Media Transcoder, put this at the top of the patch list. CISA gave US federal agencies until 2026-11-24 to deal with it, and that is a sensible deadline for a small business too.

• Patch. Update to a fixed release: openwave webtop media transcoder 1.1.22.0 or later. These versions come from NVD's configuration data, so confirm them against the advisory from Openwave Messaging Limited.
• If you cannot patch yet. Follow CISA's required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
• Check your exposure. Find out whether Openwave Messaging Limited Webtop Media Transcoder can be reached from the internet, for example a VPN portal, an admin login page or a file-transfer site. Your firewall's port-forwarding rules and your IT provider's list of public-facing systems are the quickest places to look. Exposed copies come first.
• When to call IT support. Call your IT support provider now if you run Openwave Messaging Limited Webtop Media Transcoder and cannot confirm it is updated, if it was reachable from the internet before you patched it, or if you notice accounts, sign-ins or files you do not recognise. The last two can mean the system was already hit, and checking that properly takes someone who can read the logs.

• EPSS (probability of exploitation activity in the next 30 days): 0.27%, higher than 20% of all scored CVEs (as of 2026-11-10).
• CVERadar threat level: 37/100 (see methodology).

1. Find every instance. List where Openwave Messaging Limited Webtop Media Transcoder runs, including test, DR and forgotten internet-facing systems, and record the installed version.
2. Upgrade to a fixed release. openwave webtop media transcoder: 1.1.22.0 or later. Get the build from the vendor advisory.
3. If you can't patch today, follow CISA's required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
4. Verify the fix. Re-run the version check on every instance and confirm it reports the fixed build (1.1.22.0 or later). Re-scan from outside if the service is exposed.
5. Hunt for signs of earlier compromise. If the system was exposed before you patched, assume it may have been hit and check the items below.
6. Rotate credentials stored on or used by the affected system if you cannot rule out compromise, and keep the logs you reviewed.

Detection hints

• Check the vendor advisory for indicators of compromise and review the affected system's logs back to the disclosure date.

Detection commands are generic starting points, not CVE-specific signatures. Use the indicators from the vendor advisory when it publishes them.

• NVD: CVE-2026-111793 nvd.nist.gov/vuln/detail/CVE-2026-111793
• CVE.org record www.cve.org/CVERecord?id=CVE-2026-111793
• Vendor link from CISA KEV github.com/GISOpenwave/security-advisories-public/blob/main/CAN-2026-2
• Vendor link from CISA KEV jvn.jp/en/vu/JVNVU93403064/
• CISA KEV catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
• FIRST EPSS (2026-11-10) api.first.org/data/v1/epss?cve=CVE-2026-111793