Alfresco Transformation Service (Enterprise): Server-Side Request Forgery
CVE-2026-26339 is a critical-severity server-side request forgery vulnerability in Alfresco Transformation Service (Enterprise) from Hyland, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 4.2.3 as the first without the flaw, so updating Alfresco Transformation Service (Enterprise) to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.63% chance of exploitation within 30 days, higher than 51% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Alfresco Transformation Service (Enterprise) to 4.2.3 or a later version.
- Update Alfresco Community (Transform Core) to 5.2.4 or a later version.
- Update Alfresco Transform Service to 4.2.3 or a later version.
- Read the advisory on connect.hyland.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Hyland | Alfresco Transformation Service (Enterprise) | before 4.2.3 | 4.2.3 |
| Hyland | Alfresco Community (Transform Core) | before 5.2.4 | 5.2.4 |
| Hyland | Alfresco Transform Service | before 4.2.3 | 4.2.3 |
| Hyland | Alfresco Transform Core | before 5.2.4 | 5.2.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 9.8 | Critical | CNA (vulncheck.com) |
Official description
Hyland Alfresco Transformation Service allows unauthenticated attackers to achieve remote code execution through the argument injection vulnerability, which exists in the document processing functionality.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Server-Side Request Forgery
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
How developers prevent this class of flaw
- If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
- If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
Other references
Other vulnerabilities in Alfresco Transformation Service (Enterprise)
- 9.8 Critical severity
- 8.2 High severity
Recent Server-Side Request Forgery vulnerabilities
- 7.5 High severity
- 7.6 High severity
- 8.5 High severity
- 8.5 High severity
- 9.1 Critical severity
- 9.8 Critical severity
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