CVE-2026-82439

CRITICAL
Published Sep 14, 2026 Modified Sep 14, 2026 CWE-770

Description

Description The DRPC server kept a map from function name to request queue and created an entry the first time a function name was seen. No code path ever removed an entry: request cleanup removed the request from its queue, and the shutdown path drained queues, but the queue object and its map entry remained for the life of the process. Function names come from the client and are not constrained to functions any topology has registered, so the number of retained entries is bounded only by the number of distinct names an attacker chooses to send, and each retained entry holds the name itself. `drpc.authorizer` is unset by default, so no credentials are required to reach the endpoint. The retained state is permanent rather than a transient load spike, so the effect accumulates until the DRPC server exhausts its heap. Mitigation Upgrade to 3.1.0, where a function's queue is removed once nothing is waiting in it. Users who cannot upgrade immediately should configure `drpc.authorizer` so that only trusted principals can reach the DRPC endpoints, and should ensure the DRPC ports are not reachable from untrusted networks. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.

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CVSS v3.1 Score

9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0052
Probability of exploitation
0.43%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-770 CWE-770

References

Frequently Asked Questions

What is CVE-2026-82439? +
Description The DRPC server kept a map from function name to request queue and created an entry the first time a function name was seen. No code path ever removed an entry: request cleanup removed the request from its queue, and the shutdown path drained queues, but the queue object and its map entry remained for the life of the process. Function names come from the client and are not constrained to functions any topology has registered, so the number of retained entries is bounded only by the number of distinct names an attacker chooses to send, and each retained entry holds the name itself. `drpc.authorizer` is unset by default, so no credentials are required to reach the endpoint. The retained state is permanent rather than a transient load spike, so the effect accumulates until the DRPC server exhausts its heap. Mitigation Upgrade to 3.1.0, where a function's queue is removed once nothing is waiting in it. Users who cannot upgrade immediately should configure `drpc.authorizer` so that only trusted principals can reach the DRPC endpoints, and should ensure the DRPC ports are not reachable from untrusted networks. Credit The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm. It has a CVSS v3.1 base score of 9.8 (CRITICAL).
How severe is CVE-2026-82439? +
CVE-2026-82439 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0052, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-82439? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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