Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessReach exposed Dragonfly port (unauthenticated)
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DeliverySend RANDMEMBER command with huge negative COUNT
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ExploitTrigger unbounded memory allocation
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ExecutionOOM killer terminates instance
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ImpactDenial of service for all clients
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Memory allocation limits
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| Exploitation Conditions | Exploitation requires network access to the Dragonfly service and an existing key of the matching type (a hash for HRANDFIELD, a sorted set for ZRANDMEMBER, or a set for SRANDMEMBER) holding at least one element; the attacker then supplies a large negative COUNT argument, which the vulnerable code paths allocate without bounds. No authentication is required per the CVSS vector (PR:N), so instances reachable without the optional requirepass/ACL protection or network segmentation are directly exposed. Limiting factors: the attacker must be able to reach the Dragonfly port and a qualifying key must exist (or be creatable); deployments that bind Dragonfly to localhost, enforce authentication, or firewall the datastore port substantially reduce realistic exploitability. Impact is confined to availability - crashing the instance - with no data exposure or modification. |
| Impact | This is a genuine availability-focused denial-of-service issue, not a high-CVSS-but-low-risk theoretical finding, but its impact is bounded to availability only. The provided CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H) is internally consistent with the description: a network-reachable, low-complexity, unauthenticated attack with high availability impact and no confidentiality or integrity impact. The base score of 8.7 is driven entirely by the trivial remote-unauthenticated path to a full instance crash. Mitigating the urgency: there is NO CISA KEV listing and NO explicitly flagged public exploit code in the provided intelligence, so the real-world exploitation signal is currently low despite the high severity - EPSS and SSVC data were not supplied and cannot be factored in. The attack destroys availability for ALL clients of the instance (OOM-kills the whole process), which raises operational risk for anyone exposing Dragonfly without network controls or authentication. Note a metadata conflict: the input Tags label this 'Information Disclosure,' which contradicts the description and the CVSS vector (VC:N) - this is purely an availability/DoS flaw (CWE-789, unbounded memory allocation), so the Information Disclosure classification should be disregarded. |
| Exploit ScenarioDerived | An attacker with network reachability to a Dragonfly instance (default port 6379) that lacks authentication issues a single command such as SRANDMEMBER mykey -9999999999 against a key holding even one element; because a negative COUNT permits duplicate selection, Dragonfly attempts to allocate a result set of that enormous size. The allocation exhausts host memory and triggers the Linux OOM killer, terminating the Dragonfly process and denying service to every connected client. No public exploit code is identified in the provided data, but the triggering command is trivial to reproduce from the public vulnerability description. |
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Alert meAnalysisAIv1 – Oct 15, 2026
Unauthenticated remote attackers can crash Dragonfly through 2.0.2 by issuing a single HRANDFIELD, ZRANDMEMBER, or SRANDMEMBER command with a large negative COUNT against a key holding at least one element, causing an unbounded memory allocation that drives the process into the OOM killer and terminates the instance for every connected client. The CVSS 4.0 vector (8.7) and the independent CVSS 3.1 assessment both rate this AV:N/AC:L/PR:N/UI:N with availability-only impact (C:N/I:N/A:H), so no credentials or user interaction are required out of the box, although the attacker must be able to reach the Dragonfly port and a key of the matching type must exist (or be creatable). No public exploit code has been identified at time of analysis and the issue is not listed in CISA KEV; practical risk is concentrated on internet-exposed or unauthenticated Dragonfly deployments.
RemediationAI
No vendor-released patch is identified at time of analysis, so administrators should monitor https://github.com/dragonflydb/dragonfly/issues/8578 and upgrade to the first Dragonfly release after 2.0.2 as soon as it is published. In the interim, practical compensating controls are: enable Dragonfly authentication (requirepass or ACL) so only credentialed clients can issue commands - the trade-off is that any existing unauthenticated client integrations must be updated; bind the service to localhost or an internal-only interface and firewall the datastore port (6379 by default) - the trade-off is loss of direct remote access, which should be replaced with a bastion host or an application-tier proxy; use Dragonfly ACLs to deny HRANDFIELD, ZRANDMEMBER, and SRANDMEMBER for untrusted users, and restrict write access to hash, sorted set, and set keys - the trade-off is loss of those randomization commands and reduced flexibility for legitimate clients; and run the process under a cgroup memory limit with restart supervision plus replica failover so an OOM kill causes a fast restart rather than host-wide memory pressure - the trade-off is that the instance can still be terminated, so this only limits blast radius and recovery time. Additionally, alert on abnormal large allocations and OOM-kill events, and keep Dragonfly off any untrusted network until an official fix is available.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
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Technical ContextAI · show details
DragonflyDB is a multi-threaded, Redis- and Memcached-compatible in-memory datastore written in C++, and the flaw maps to CWE-789 (Memory Allocation with Excessive Size Value). The three affected commands - HRANDFIELD (hash; src/server/hset_family.cc, roughly lines 1436-1483 at commit 8ce4bbb), ZRANDMEMBER (sorted set; src/server/zset_family.cc, roughly lines 1519-1522), and SRANDMEMBER (set; src/server/set_family.cc, roughly lines 957-984) - each take a COUNT argument. Redis-compatible semantics allow a negative COUNT to request up to |COUNT| distinct random elements, but these Dragonfly code paths use the supplied value to size an allocation or reserve without bounding it, so a very large negative number is effectively treated as an enormous allocation request. The precondition is minimal: a single existing key of the matching data type with one or more elements, which an attacker may also be able to create if write access is permitted. The CPE string cpe:2.3:a:dragonflydb:dragonfly:*:*:*:*:*:*:*:* indicates the flaw applies to Dragonfly across released versions up to and including 2.0.2; nothing in the provided data suggests an information-disclosure component despite the attached tags, and the authoritative assessment confirms impact is confined to availability.
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Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Remote, low-complexity, unauthenticated single-command trigger (AV:N/AC:L/PR:N/UI:N) with full instance crash and no confidentiality or integrity impact, so A:H only.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
DescriptionCVE.org
Dragonfly through 2.0.2 contains an unbounded memory allocation vulnerability that allows unauthenticated clients to exhaust memory by passing a negative COUNT to HRANDFIELD, ZRANDMEMBER or SRANDMEMBER. Attackers can send a single command against a one-element key with a huge negative COUNT to trigger the OOM killer, terminating the instance for all clients.
Executive ViewAI
Dragonfly through 2.0.2 has an unauthenticated remote denial-of-service vulnerability that can terminate the service instance and disrupt every connected client. No public exploit identified at time of analysis, but internet-exposed or unauthenticated deployments carry the greatest practical risk because an attacker who can reach the Dragonfly port can exhaust memory and force a full outage without credentials. Leadership should care because Dragonfly outages can interrupt applications, customers, and internal services that depend on it for caching or data operations.
No vendor-released patch identified at time of analysis; interim mitigations include removing internet exposure, restricting the Dragonfly port to trusted networks, enabling authentication where supported, segmenting the service, applying connection and request rate limits, monitoring for OOM/crash events, and blocking or rate-limiting the affected HRANDFIELD, ZRANDMEMBER, and SRANDMEMBER commands through a proxy or application-layer control.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
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EUVD-2026-102470
GHSA-w5x4-fq2q-m366
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB