CVE-2026-40453

CVE-2026-40453 is a critical-severity vulnerability in Apache Camel with a CVSS 3.x base score of 9.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-178.

Key facts

Description

The fix for CVE-2025-27636 added setLowerCase(true) to HttpHeaderFilterStrategy so that case-variant header names such as 'CAmelExecCommandExecutable' are filtered out alongside 'CamelExecCommandExecutable'. The same setLowerCase(true) call was not applied to five non-HTTP HeaderFilterStrategy implementations: JmsHeaderFilterStrategy and ClassicJmsHeaderFilterStrategy in camel-jms, SjmsHeaderFilterStrategy in camel-sjms, CoAPHeaderFilterStrategy in camel-coap, and GooglePubsubHeaderFilterStrategy in camel-google-pubsub. Because those strategies use case-sensitive String.startsWith('Camel'/'camel') filtering while the Camel Exchange stores headers in a case-insensitive map, an attacker with JMS (or equivalent) producer access to the broker consumed by a Camel route can inject case-variant Camel internal headers, which are then resolved by downstream components such as camel-exec and camel-file using their canonical casing. This enables remote code execution and arbitrary file write on routes that forward JMS messages to header-driven components. This issue affects Apache Camel: from 3.0.0 before 4.14.6, from 4.15.0 before 4.18.2, from 4.19.0 before 4.20.0. Users are recommended to upgrade to version 4.20.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.6. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.2.

Frequently asked questions

What is CVE-2026-40453?
The fix for CVE-2025-27636 added setLowerCase(true) to HttpHeaderFilterStrategy so that case-variant header names such as 'CAmelExecCommandExecutable' are filtered out alongside 'CamelExecCommandExecutable'. The same setLowerCase(true) call was not applied to five non-HTTP HeaderFilterStrategy implementations: JmsHeaderFilterStrategy and ClassicJmsHeaderFilterStrategy in camel-jms, SjmsHeaderFilterStrategy in camel-sjms, CoAPHeaderFilterStrategy in camel-coap, and GooglePubsubHeaderFilterStrategy in camel-google-pubsub. Because those strategies use case-sensitive String.startsWith('Camel'/'camel') filtering while the Camel Exchange stores headers in a case-insensitive map, an attacker with JMS (or equivalent) producer access to the broker consumed by a Camel route can inject case-variant Camel internal headers, which are then resolved by downstream components such as camel-exec and camel-file using their canonical casing. This enables remote code execution and arbitrary file write on routes that forward JMS messages to header-driven components. This issue affects Apache Camel: from 3.0.0 before 4.14.6, from 4.15.0 before 4.18.2, from 4.19.0 before 4.20.0. Users are recommended to upgrade to version 4.20.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.6. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.2.
How severe is CVE-2026-40453?
CVE-2026-40453 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40453 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40453?
CVE-2026-40453 primarily affects Apache Camel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-40453?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-40453 have an EU (EUVD) identifier?
Yes. CVE-2026-40453 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-25791.
When was CVE-2026-40453 published?
CVE-2026-40453 was published on 2026-04-27 and last updated on 2026-06-27.

References

Affected products (2)

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