core: XML Injection
CVE-2026-53582 is a high-severity XML injection vulnerability in core from Opnsense, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected core versions: < 26.1.10. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.73% chance of exploitation within 30 days, higher than 55% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of core you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:L. Scored by CNA (github.com).
Official description
OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.10, the Trust module stores attacker-controlled certificate authority and certificate refid values and interpolates them into XPath expressions in src/opnsense/mvc/app/models/OPNsense/Trust/FieldTypes/CAsField.php and src/opnsense/mvc/app/models/OPNsense/Trust/FieldTypes/CertificatesField.php. A user with CA Manager or Certificate Manager privileges can submit a crafted refid and repeatedly retrieve the object to obtain a boolean refcount oracle, allowing values in config.xml to be recovered character by character. Exposed values can include password hashes, API credentials, certificate private keys, VPN key material, and high-availability credentials, enabling privilege escalation and compromise of other security domains. This issue is fixed in version 26.1.10.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: XML Injection
The product does not properly neutralize special elements that are used in XML, allowing attackers to modify the syntax, content, or commands of the XML before it is processed by an end system.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Other vulnerabilities in core
- 8.1 High severity
- 7.2 High severity
- 7.1 High severity
- 8.1 High severity
- 8.0 High severity
- 9.9 Critical severity
Recent XML Injection vulnerabilities
- 8.1 High severity
- 7.1 High severity
- 9.8 Critical severity
- 7.7 High severity
- 8.1 High severity
- 7.8 High severity
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