How severe is CVE-2025-27817?

CVE-2025-27817 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2025-27817?

CVE-2025-27817 affects the following packages: org.apache.kafka:kafka-clients (Maven). Ecosystems affected: Maven.

How do I fix CVE-2025-27817?

Update org.apache.kafka:kafka-clients to 3.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-27817 is resolved across your whole dependency graph.

How do I detect CVE-2025-27817 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.kafka:kafka-clients. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2025-27817 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-2025-27817?

O3 pinpoints whether CVE-2025-27817 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2025-27817 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2025-27817, including . All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2025-27817?

CVE-2025-27817 has an EPSS (Exploit Prediction Scoring System) score of 60.8%, placing it in the 99th 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. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

What type of vulnerability is CVE-2025-27817?

CVE-2025-27817 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for CVE-2025-27817?

A Nuclei detection template exists for CVE-2025-27817, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2025-27817 published, and has it been updated?

CVE-2025-27817 was published on June 10, 2025 and was last updated on March 15, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2025-27817: kafka-clients Server-Side Request Forgery (High…

EPSS Exploitation Probability

via FIRST.org ↗

60.8%probability of exploitation in next 30 days

High Risk99th percentile+39.42%

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.

Blast Radius

1 pkg affected

☕org.apache.kafka:kafka-clients

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

A possible arbitrary file read and SSRF vulnerability has been identified in Apache Kafka Client. Apache Kafka Clients accept configuration data for setting the SASL/OAUTHBEARER connection with the brokers, including "sasl.oauthbearer.token.endpoint.url" and "sasl.oauthbearer.jwks.endpoint.url". Apache Kafka allows clients to read an arbitrary file and return the content in the error log, or sending requests to an unintended location. In applications where Apache Kafka Clients configurations can be specified by an untrusted party, attackers may use the "sasl.oauthbearer.token.endpoint.url" and "sasl.oauthbearer.jwks.endpoint.url" configuratin to read arbitrary contents of the disk and environment variables or make requests to an unintended location. In particular, this flaw may be used in Apache Kafka Connect to escalate from REST API access to filesystem/environment/URL access, which may be undesirable in certain environments, including SaaS products.

Since Apache Kafka 3.9.1/4.0.0, we have added a system property ("-Dorg.apache.kafka.sasl.oauthbearer.allowed.urls") to set the allowed urls in SASL JAAS configuration. In 3.9.1, it accepts all urls by default for backward compatibility. However in 4.0.0 and newer, the default value is empty list and users have to set the allowed urls explicitly.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.kafka:kafka-clients`	≥ 3.1.0&&< 3.9.1	3.9.1

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.kafka:kafka-clients. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.apache.kafka:kafka-clients to 3.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-27817 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 pinpoints whether CVE-2025-27817 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2025-27817. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A possible arbitrary file read and SSRF vulnerability has been identified in Apache Kafka Client. Apache Kafka Clients accept configuration data for setting the SASL/OAUTHBEARER connection with the brokers, including "sasl.oauthbearer.token.endpoint.url" and "sasl.oauthbearer.jwks.endpoint.url". Apache Kafka allows clients to read an arbitrary file and return the content in the error log, or sending requests to an unintended location. In applications where Apache Kafka Clients configurations can be specified by an untrusted party, attackers may use the "sasl.oauthbearer.token.endpoint.url" and

O3 Security · Impact-Aware SCA

Is CVE-2025-27817 in your dependencies?

O3 detects CVE-2025-27817 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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CVE-2025-27817