Improper Neutralization of Special Elements in Output Used by a Downstream Component…
CVE-2026-48203 is a critical-severity improper input validation vulnerability in Apache Camel from Apache, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 4.14.8, 4.18.3, 4.21.0 as the first without the flaw, so updating Apache Camel to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.6% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Apache Camel to 4.14.8 or 4.18.3 or 4.21.0, whichever matches your release line, or a later version.
- Update Camel to 4.14.8 or 4.18.3 or 4.21.0, whichever matches your release line, or a later version.
- Read the advisory on camel.apache.org 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 |
|---|---|---|---|
| Apache | Apache Camel | 4.0.0 up to, but not including, 4.14.8; 4.15.0 up to, but not including, 4.18.3; 4.19.0 up to, but not including, 4.21.0 | 4.14.8, 4.18.3, 4.21.0 |
| Apache | Camel | 4.0.0 up to, but not including, 4.14.8; 4.15.0 up to, but not including, 4.18.3; 4.19.0 up to, but not including, 4.21.0 | 4.14.8, 4.18.3, 4.21.0 |
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
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CISA (ADP).
Official description
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection'), Improper Input Validation, Server-Side Request Forgery (SSRF) vulnerability in Apache Camel Solr component. The camel-solr producer copies Exchange message headers whose names begin with the SolrParam. prefix into the parameters of the Solr request, and headers whose names begin with the SolrField. prefix into the fields of the indexed Solr document. The prefix constants (SolrConstants.HEADER_PARAM_PREFIX / HEADER_FIELD_PREFIX) were the plain strings SolrParam. / SolrField.. Because these names do not start with the Camel / camel prefix, HttpHeaderFilterStrategy - which blocks only the Camel header namespace on the HTTP boundary - let them pass from an inbound HTTP request straight into the Exchange. In a route that bridges an HTTP consumer (for example platform-http) into a solr: producer, any HTTP client could therefore set SolrParam.* headers to inject arbitrary Solr request parameters - including shards or stream.url, which cause the Solr server to issue server-side requests to an attacker-chosen URL (server-side request forgery, for example to an internal service or a cloud metadata endpoint), or qt to reach administrative request handlers - and set SolrField.* headers to inject arbitrary fields into indexed documents. No credentials are required when the bridging consumer is unauthenticated. This issue affects Apache Camel: from 4.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0. Users are recommended to upgrade to version 4.21.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.8. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. After upgrading, routes that set Solr parameters or fields via the raw header prefixes must use CamelSolrParam. / CamelSolrField. instead of SolrParam. / SolrField.. For deployments that cannot upgrade immediately, strip the SolrParam.* and SolrField.* headers from any untrusted ingress before the solr: producer, and set the required Solr parameters and fields from a trusted source in the route.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
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
Advisories
Third-party and government advisories
- openwall.com/lists/oss-security/2026/07/05/17Mailing List, Third Party Advisory
Other vulnerabilities in Apache Camel
- 7.5 High severity
- 8.8 High severity
- 8.2 High severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
Recent Improper Input Validation vulnerabilities
- 7.5 High severity
- 10.0 Critical severity
- 7.3 High severity
- 7.3 High severity
- 7.3 High severity
- 9.8 Critical severity
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