CVE-2026-82439
CVE-2026-82439 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. 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-770.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- EPSS exploit prediction: 1% (43rd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-770
- Published:
- Last modified:
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.
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.
- How severe is CVE-2026-82439?
- CVE-2026-82439 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2026-82439 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-82439?
- 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.
- When was CVE-2026-82439 published?
- CVE-2026-82439 was published on 2026-09-14.
References
- https://lists.apache.org/thread/7sgzvv5lzz93jn6vy74qfk105bhmkrzs
- http://www.openwall.com/lists/oss-security/2026/09/13/18
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