Improper Input Validation, Exposure of Sensitive Information to an Unauthorized Actor…
CVE-2026-55993 is a high-severity improper input validation vulnerability in Apache Camel Atmosphere Websocket from Apache, with a CVSS 3.1 base score of 7.5 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 Atmosphere Websocket to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.86% chance of exploitation within 30 days, higher than 59% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Apache Camel Atmosphere Websocket 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 Atmosphere Websocket | 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
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CISA (ADP).
Official description
Improper Input Validation, Exposure of Sensitive Information to an Unauthorized Actor, Server-Side Request Forgery (SSRF) vulnerability in Apache Camel in Atmosphere Websocket Component. The camel-atmosphere-websocket consumer mapped inbound WebSocket query parameters into the Camel Exchange header map without applying any HeaderFilterStrategy (WebsocketConsumer.sendEventNotification() iterates the query-string map collected in WebsocketConsumer.service() and copies each entry into the Exchange). Because nothing blocked the Camel header namespace, a client connecting to the WebSocket endpoint could set Camel-internal control headers - including CamelHttpUri (Exchange.HTTP_URI) - simply by supplying them as query parameters. In a route where the WebSocket consumer feeds a downstream HTTP producer, the injected CamelHttpUri redirects the server-side HTTP request to an attacker-chosen destination (server-side request forgery - for example to an internal service or a cloud metadata endpoint). In addition, the HTTP producer resolves Camel property placeholders on the resulting (attacker-controlled) URI, so placeholders embedded in the injected value - such as an environment-variable reference, an application property, or a vault reference - are resolved to their real values and sent to the attacker, disclosing environment variables, application properties and vault secrets. When the WebSocket endpoint is exposed without authentication, this is reachable by an unauthenticated remote attacker. 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. The fix makes the consumer apply the HeaderFilterStrategy it already inherits from the HTTP/servlet stack, filtering the Camel header namespace case-insensitively on inbound mapping, so externally-supplied Camel* / camel* headers are no longer copied into the Exchange. For deployments that cannot upgrade immediately, strip the Camel control headers from the inbound message before they reach any downstream producer (for example removeHeaders('Camel*') and removeHeaders('camel*') at the start of the route), require authentication on the WebSocket endpoint, and avoid bridging an untrusted consumer directly into an HTTP producer whose target URI can be driven from message headers.
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: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- openwall.com/lists/oss-security/2026/07/05/27Third Party Advisory
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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