# What is CVE-2026-20230?

> CVE-2026-20230 is a high-severity flaw (CVSS 8.6) in Unified Communications Manager from Cisco, published on 3 June 2026. It is on the list of flaws known to be exploited, so criminals are already using it. The latest forecast puts its chance of use in the next 30 days at 88%. If you run an affected version, patch it first.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2026-20230

## At a glance

- **Verdict:** Fix this now. Attackers are using this flaw today. If you run an affected version, it goes to the top of your list.
- **Precursor Intelligence risk score:** 75 out of 100 (High); action: Emergency patch. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 8.6 out of 10)
- **Known to be exploited:** Yes, it is on the government list of flaws known to be exploited
- **Chance of use in the next 30 days:** 88% (latest exploit-likelihood forecast)
- **Published:** 3 June 2026
- **Record last updated:** 7 October 2026
- **Main product:** Unified Communications Manager from Cisco
- **Affected products:** 1

## What is CVE-2026-20230? In plain terms

It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can change data.

### The official description

A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an unauthenticated, remote attacker to conduct server-side request forgery (SSRF) attacks through an affected device.

This vulnerability is due to improper input validation for specific HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to write files to the underlying operating system that could be used later to elevate to root.
Note: Cisco has assigned this security advisory a Security Impact Rating (SIR) of Critical rather than High as the score indicates. The reason is that exploitation of this vulnerability could result in an attacker elevating privileges to root.
Note: To exploit this vulnerability, the WebDialer service must be enabled. WebDialer is disabled by default.

### What kind of flaw is it?

- CWE-918: Server-Side Request Forgery (SSRF)

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can change data

Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N`

## Is CVE-2026-20230 being exploited? Yes

Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 88%.

Exploit likelihood over the last 7 days: 88%, 88%, 88%, 88%, 88%, 88%, 88%.

### Timeline

- 3 June 2026: Published
- 24 June 2026: Exploit likelihood jumped
- 26 June 2026: Added to the known-exploited list
- 7 October 2026: Record last updated

### How Precursor Intelligence ranks it

CVE-2026-20230 scores **75 out of 100 (High)**, with the action "Emergency patch".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2026-20230?

The published record lists 1 product. Versions are as published: "14.0 to before 14su6" means from 14.0 up to, but not including, 14su6.

- [Unified Communications Manager](https://www.precursorintelligence.com/product/cisco/unified_communications_manager) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Application): 14.0 to before 14su6, 15.0 to 15su4a

## How do I fix CVE-2026-20230?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Check it wasn’t used before you patched.** Because criminals are already using this flaw, look for signs of a break-in on affected systems using the vendor’s guidance.

### References

- [sec.cloudapps.cisco.com](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cucm-ssrf-cXPnHcW) (Vendor advisory)
- [denizhalil.com](https://denizhalil.com/2026/06/12/cve-2026-20230-cisco-unified-cm-ssrf/) (Exploit, Third-party advisory)
- [cisa.gov](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20230) (Government resource)

## Questions

### What is CVE-2026-20230?

CVE-2026-20230 is a high-severity flaw in Unified Communications Manager from Cisco, published on 3 June 2026. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can change data.

### How serious is CVE-2026-20230?

It scores 8.6 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2026-20230 is 75 out of 100, which is High. Its action is "Emergency patch". Attackers are using this flaw today. If you run an affected version, it goes to the top of your list.

### Is CVE-2026-20230 being exploited?

Attackers are already using it. It is on the government list of flaws known to be exploited, and the latest forecast puts the chance of it being used in the next 30 days at 88%.

### Which versions does CVE-2026-20230 affect?

For Unified Communications Manager from Cisco: 14.0 to before 14su6, 15.0 to 15su4a.

### How do I fix CVE-2026-20230?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet. Because criminals are already using it, also check affected systems for signs of a break-in.

## Does CVE-2026-20230 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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