kyverno: Server-Side Request Forgery
CVE-2026-100705 is a high-severity server-side request forgery vulnerability in kyverno, with a CVSS 3.1 base score of 7.6 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. The record lists version 1.19.1 as the first without the flaw, so updating kyverno to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.2% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update kyverno to 1.19.1 or a later version.
- 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
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- 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
- LowLimited modification of data is possible.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.3 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.6 | High | CNA (vulncheck.com) |
Official description
Kyverno before 1.19.1 is vulnerable to server-side request forgery. The default egress blocklist (169.254.169.254, 169.254.169.253, metadata.google.internal, 127.0.0.0/8, ::1/128) and the scoped-token control were wired only into the new CEL http.Get/Post library and were never applied to the legacy apiCall service executor (pkg/engine/apicall/executor.go) or to the GlobalContextEntry external-API path, which handle every non-CEL context[].apiCall.service call. Because these paths use a plain net/http client with no egress filtering and no validation of the configured service URL, a ClusterPolicy or GlobalContextEntry author — or, where a deployed policy templates the service URL from the admission resource, a lower-privileged resource submitter — can cause Kyverno to issue GET/POST requests to an arbitrary host, including the cloud metadata endpoint, loopback, and any in-cluster service, reading cloud instance credentials and reaching internal endpoints with Kyverno's network position. The executor also unconditionally attaches Kyverno's projected ServiceAccount token to the attacker-chosen destination; the token is audience-scoped, limiting its replay value. Fixed in 1.19.1.
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: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in kyverno
- 8.8 High severity
- 9.9 Critical severity
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
- 7.7 High severity
Recent Server-Side Request Forgery vulnerabilities
- 8.6 High severity
- 8.2 High severity
- 7.1 High severity
- 8.2 High severity
- 7.3 High severity
- 8.1 High severity
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