dragonfly: Double Free
CVE-2026-104192 is a critical-severity double free vulnerability in dragonfly from DragonflyDB, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected dragonfly versions: < 1.40. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.28% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of dragonfly you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Dragonflydb | dragonfly | < 1.40 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (github.com).
Official description
Dragonfly is an in-memory data store built for modern application workloads. Prior to 1.40, OpaqueObjLoader::CreateStream in src/server/rdb_load.cc can associate one streamNACK with a consumer group's global PEL and a consumer-local PEL, then free the shared object when a duplicate consumer entry is rejected. Cleanup subsequently frees the same object again. In the default configuration, where Dragonfly ships with authentication disabled, an unauthenticated client can trigger the double-free by sending a crafted serialized stream to RESTORE, causing allocator corruption, denial of service, and potentially attacker-controlled code execution as the Dragonfly service account. The source fix has not yet been mapped to a published release.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
References
Patches and release notes
Other vulnerabilities in dragonfly
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
- 9.4 Critical severity
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.5 High severity
- 8.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.8 High severity
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