How severe is CVE-2026-63621?

CVE-2026-63621 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-63621?

CVE-2026-63621 affects the following packages: org.apache.camel:camel-knative (Maven), org.apache.camel:camel-knative (Maven), org.apache.camel:camel-knative (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-63621?

Update org.apache.camel:camel-knative to 4.14.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-63621 is resolved across your whole dependency graph.

How do I detect CVE-2026-63621 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.camel:camel-knative, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-63621 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-63621?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-63621 can be triaged on real exposure rather than presence alone.

Is CVE-2026-63621 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-63621 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-63621?

CVE-2026-63621 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 29th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2026-63621 published, and has it been updated?

CVE-2026-63621 was published on August 24, 2026 and was last updated on August 29, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2026-63621 — camel-knative

MEDIUM

CVE-2026-63621 is a medium-severity (CVSS 5.3) vulnerability in org.apache.camel:camel-knative. A fix is available for org.apache.camel:camel-knative — see the affected versions and patch details below.

Apache Camel: Camel-Knative: CloudEvent extension fields received in structured content mode were mapped onto message headers without applying any header filter strategy

Also known asGHSA-vvwm-3j43-7pfm

Published

Aug 24, 2026

Updated

Aug 29, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Sep 19, 2026 · OSV.dev, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-63621.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs29th percentile — riskier than 29% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2026-63621 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

3 pkgs affected

☕org.apache.camel:camel-knative☕org.apache.camel:camel-knative☕org.apache.camel:camel-knative

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Improper Input Validation, Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') vulnerability in Apache Camel Knative component

The Knative consumer in camel-knative maps inbound CloudEvent attributes onto Camel message headers. In binary content mode the HTTP-header path filters Camel-internal headers through KnativeHttpHeaderFilterStrategy, but in structured content mode (Content-Type application/cloudevents+json) the CloudEvent extension fields are read directly from the JSON body and every extension key is copied into the Exchange headers without applying any HeaderFilterStrategy (CloudEventProcessors, spec versions 1.0, 1.0.1 and 1.0.2). As a result, an unauthenticated attacker can inject Camel-internal headers (e.g. CamelHttpUri, CamelHttpPath, CamelFileName) via a structured-mode CloudEvent request, matched case-insensitively against Camel's header map. When a route forwards messages from a Knative consumer to a header-driven component such as camel-http or camel-file, the injected headers override configured values, enabling server-side request forgery (SSRF), path traversal or message-dispatch redirection depending on the route. This is an incomplete fix of the inbound header filtering previously added for the binary content-mode path, and is the same pattern addressed in camel-cxf/camel-knative (CVE-2026-47323), camel-undertow (CVE-2025-30177), the broader incoming-header filter (CVE-2025-27636 and CVE-2025-29891), and the non-HTTP strategies (CVE-2026-40453).

This issue affects Apache Camel: from 3.15.0 before 4.14.9, from 4.15.0 before 4.18.4, from 4.19.0 before 4.21.0.

Users are recommended to upgrade to version 4.22.0, which fixes the issue. If users are on the 4.18.x LTS releases stream, then they are suggested to upgrade to 4.18.4. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.9. The non-LTS releases 4.15.0 through 4.17.0 and 4.19.0 through 4.21.0 are affected but do not receive a maintenance fix; users on those versions should upgrade to 4.18.4 or 4.22.0.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.camel:camel-knative`	≥ 3.15.0&&< 4.14.9	4.14.9`org.apache.camel:camel-knative:4.14.9`
☕Maven	`org.apache.camel:camel-knative`	≥ 4.15.0&&< 4.18.4	4.18.4`org.apache.camel:camel-knative:4.18.4`
☕Maven	`org.apache.camel:camel-knative`	≥ 4.19.0&&< 4.22.0	4.22.0`org.apache.camel:camel-knative:4.22.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.camel:camel-knative, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.camel:camel-knative to 4.14.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-63621 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-63621 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-63621. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Improper Input Validation, Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') vulnerability in Apache Camel Knative component The Knative consumer in camel-knative maps inbound CloudEvent attributes onto Camel message headers. In binary content mode the HTTP-header path filters Camel-internal headers through KnativeHttpHeaderFilterStrategy, but in structured content mode (Content-Type application/cloudevents+json) the CloudEvent extension fields are read directly from the JSON body and every extension key is copied into the Exchange headers with

O3 Security · Impact-Aware SCA

Is CVE-2026-63621 in your dependencies?

O3 Security finds CVE-2026-63621 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works