Skip to main content

FalkorDB EUVDEUVD-2026-95474

| CVE-2026-7827 CRITICAL
Stack-based Buffer Overflow (CWE-121)
2026-10-09 securin GHSA-fwp9-2ghh-pw8g
9.2
CVSS 4.0 · Vendor: securin
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Reach unauthenticated FalkorDB/Redis port
  2. Delivery
    Issue REPLICAOF to attacker-controlled master
  3. Exploit
    Deliver crafted RDB with oversized property count
  4. Execution
    Overflow variable-length stack arrays in _RdbLoadEntity
  5. Impact
    Crash service or execute arbitrary code

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Stack buffer bounds checking
MITRE ATT&CK

1 technique across 1 tactic: Execution

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Exploitation requires the attacker to be able to issue Redis replication commands (e.g., REPLICAOF/SLAVEOF) so the FalkorDB instance loads an attacker-supplied RDB stream whose entity property count is attacker-controlled and unbounded; the decoder (_RdbLoadEntity in src/serializers/decoders/*/decode_graph_entities.c) then sizes two variable-length thread-stack arrays from that count and fills them, overflowing the stack. The concrete enabling condition named in the description is an instance with NO password configured (requirepass/ACL unset) that is network-reachable, which makes the replication commands unauthenticated. LIMITING FACTORS: if a password or ACLs are configured the attacker needs valid credentials to initiate replication; reliable arbitrary code execution (versus DoS) is non-trivial given stack overflow exploitation and corresponds to the CVSS AC:H rating; only versions before 4.18.4 are affected.

Impact

Signals point to a genuinely serious but not yet actively-exploited flaw whose real-world urgency is bounded by deployment context. The vendor-assigned CVSS 4.0 vector (AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H) yields 9.2 Critical, driven by network reach, no required privileges, and high confidentiality/integrity/availability impact; AC:H appropriately reflects that an attacker must stand up a replication master and craft a malformed RDB stream, and for code execution must defeat stack layout/mitigations. PR:N is defensible ONLY for the stated no-password scenario - against a FalkorDB/Redis instance with requirepass or ACLs set, replication commands require credentials, so effective privilege rises. No EPSS score, no CISA KEV listing, and no public POC were provided in the input, so exploitation status is 'no public exploit identified at time of analysis' - there is no evidence of in-the-wild use. The root cause is firmly confirmed by the vendor source diff (variable-length stack arrays sized by an unbounded attacker-controlled count, now capped at UINT16_MAX with a 256-element stack threshold and a heap path). Net: this is a real priority for anyone exposing an unauthenticated FalkorDB instance to untrusted networks, where DoS is trivially achievable, but RCE remains the description's 'possibly' (not demonstrated) and the niche product footprint plus AC:H temper the likelihood of mass exploitation versus targeted abuse of misconfigured, internet-exposed instances.

Exploit ScenarioDerived

An attacker who can reach a FalkorDB instance that has no password configured issues Redis replication commands (e.g., REPLICAOF/SLAVEOF) pointing the victim at an attacker-controlled master, then serves a crafted RDB stream declaring a huge entity property count. When _RdbLoadEntity sizes two variable-length stack arrays from that unbounded count and fills them with attacker data, the thread stack is overrun, reliably crashing the service (DoS) and possibly enabling arbitrary code execution. No public exploit code was identified in the provided data, and the network vector is tempered by AC:H (crafting the RDB and achieving reliable RCE is non-trivial).

Act Now Prioritize within 24-48h. Why: CRITICAL severity.
Patch available 0.6% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Oct 09, 2026

Stack-based buffer overflow in FalkorDB versions before 4.18.4 allows remote attackers who can issue Redis replication commands - for example against a network-reachable instance with no password configured - to crash the graph database and possibly achieve code execution by supplying a crafted RDB stream whose entity property count is unbounded. The decoder sizes two variable-length arrays on the thread stack from that attacker-controlled count and then fills them with attacker-supplied values, so a single malformed RDB payload overflows the stack (CWE-121). No public exploit code or confirmed active exploitation has been identified at time of analysis, and the vendor has released FalkorDB 4.18.4 moving large property sets to the heap; CVSS 4.0 rates this 9.2 with AV:N/AC:H/PR:N/UI:N, where the high attack complexity reflects the difficulty of converting the overflow into reliable arbitrary code execution rather than a denial of service.

RemediationAI

Vendor-released patch: upgrade to FalkorDB 4.18.4 (https://github.com/FalkorDB/FalkorDB/releases/tag/v4.18.4), which incorporates PR 1973 / commit 7d15431aadf37588fadc2578b90c3afb5e8daa94 and replaces the unbounded variable-length stack arrays in _RdbLoadEntity with a 256-element stack fast path plus rm_malloc heap allocation for larger property counts, adding ASSERT(n <= UINT16_MAX) as a sanity bound; this is the only complete fix and is the recommended action for all pre-4.18.4 instances, especially those exposed beyond localhost. If immediate upgrade is not possible, the highest-value compensating control is to configure requirepass and/or ACLs (or enable Redis protected-mode) so that replication commands such as REPLICAOF/SLAVEOF require authentication - this removes the unauthenticated path named in the description, but be aware it does not eliminate the overflow itself: any client holding credentials with replication privileges, or any access to the underlying RDB file, can still supply a malicious stream, so treat it as a risk reduction rather than a fix. In parallel, restrict network reachability of the Redis/FalkorDB port via bind directives, firewall rules, or a private network so untrusted hosts cannot open a replication session (trade-off: may break legitimate cross-host replication topologies), avoid loading RDB snapshots or streams from untrusted sources during recovery, and monitor logs and command traffic for unexpected REPLICAOF/SLAVEOF directives or replica connections pointing at attacker-controlled masters, which is the observable signature of an exploitation attempt; because no public exploit code has been identified, detection is primarily anomaly-based rather than signature-based.

Affected VersionsENISA

FalkorDB 0 <4.18.4

Affected Packages

euvd falkordb fix: 4.18.4

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

FalkorDB is a Redis-module graph database that persists graphs using RDB serialization, so a replica or restarting node rebuilds its data structures by replaying an RDB stream through version-specific decoders under src/serializers/decoders/ (for example current/v19, prev/v10, prev/v11). Inside _RdbLoadEntity, the on-disk format is a property count N followed by N pairs of attribute ID and typed value; the vulnerable code read that count with RedisModule_LoadUnsigned/SerializerIO_ReadUnsigned into a uint64_t and then declared two variable-length arrays, SIValue vals[n] and AttributeID ids[n], directly on the thread stack without any upper bound and looped over N entries. Because N originates from the untrusted RDB payload, an oversized value causes a classic CWE-121 stack-based buffer overflow in which attacker-supplied IDs and values are written past the end of both arrays, corrupting adjacent stack memory (return addresses and locals), which can terminate the process or, with sufficient control, redirect execution. The fix (PR 1973, commit 7d15431aadf37588fadc2578b90c3afb5e8daa94, shipped in v4.18.4) caps the stack path at ENTITY_PROP_STACK_THRESHOLD = 256 elements, allocates the arrays via rm_malloc on the heap above that threshold, and adds ASSERT(n <= UINT16_MAX), while preserving the same decoding semantics - confirming that the root cause was purely the unvalidated variable-length stack allocation. The affected CPE is the wildcard cpe:2.3:a:falkordb:falkordb:*:*:*:*:*:*:*:*, and the flaw exists in multiple bundled decoder versions, so any pre-4.18.4 build is exposed regardless of which serializer version it uses.

Know when Redis gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (securin) PRIMARY 9.2 CRITICAL
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
vuln.today AI 8.1 HIGH

Network-reachable with no auth on the described no-password instance (AV:N/PR:N); AC:H because the attacker must drive replication and craft an RDB stream and defeat stack layout for RCE; full C/I/A impact from possible code execution, scope unchanged.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (securin).

CVSS VectorVendor: securin

Attack Vector
Network
Attack Complexity
High
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
High
Vulnerable system: Availability
High
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

DescriptionCVE.org

A stack-based buffer overflow in the _RdbLoadEntity function of the RDB graph decoders (src/serializers/decoders/*/decode_graph_entities.c) in FalkorDB before 4.18.4 allows a remote attacker who can issue Redis replication commands (for example, against an instance with no password configured) to cause a denial of service and possibly execute arbitrary code by supplying a crafted RDB stream with an attacker-controlled entity property count. The count sizes two variable-length arrays on the thread stack with no upper bound, and the decoder then fills them with attacker-supplied values.

Executive ViewAI

Why It Matters

FalkorDB deployments running versions earlier than 4.18.4 are exposed to a critical remote stack overflow that any network-reachable instance can be crashed, and potentially taken over, by an unauthenticated attacker able to reach the Redis replication interface - which is the default state for instances left without a password. Because the same channel could plausibly be escalated to code execution, the exposure is not limited to availability: any graph data, connected applications, and downstream services relying on that instance sit behind a single externally reachable port. Leadership should treat this as an urgent internet-facing surface reduction and patch priority rather than a routine database update.

Business Impact: High
Compensating Controls

Apply vendor patch. Until FalkorDB 4.18.4 is deployed, restrict network access to the Redis replication port to trusted hosts only, require authentication (requirepass) on all instances, and monitor for anomalous replication or RDB synchronization activity; per the CVSS vector the flaw is remotely exploitable without authentication (PR:N) on a network-reachable instance.

Threat Intelligence Overview

EPSS Score
0.6%
Top 54% exploitable
Prevalence
Low
niche graph database, limited production/enterprise deployment footprint
Social Media
2
Sightings
Data Quality
6 sources
Confidence: High
EUVD NVD CVE.org EPSS Vulnrichment CIRCL GitHub VulDB

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.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC No
EPSS 0.6%
Patch available Yes
Active threat No
Deciding rule
CRITICAL severity
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
No
Human Impact
High
Technical Impact
Total

Priority Score

47
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +46
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

A stack-based buffer overflow occurs when a program writes more data to a buffer located on the stack than it was allocated to hold.

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

More in Redis

View all
CVE-2026-48172 CRITICAL POC
10.0 May 21

Privilege escalation to root in the LiteSpeed User-End cPanel Plugin (versions 2.3 through before 2.4.5) lets attackers

CVE-2025-49844 CRITICAL POC
9.9 Oct 03

UAF in Redis 8.2.1 via crafted Lua scripts by authenticated users. EPSS 12.4%. Patch available.

CVE-2022-0543 CRITICAL POC
10.0 Feb 18

It was discovered, that redis, a persistent key-value database, due to a packaging issue, is prone to a (Debian-specific

CVE-2018-11218 CRITICAL POC
9.8 Jun 17

Memory Corruption was discovered in the cmsgpack library in the Lua subsystem in Redis before 3.2.12, 4.x before 4.0.10,

CVE-2025-46817 HIGH POC
7.0 Oct 03

Redis is an open source, in-memory database that persists on disk. Versions 8.2.1 and below allow an authenticated user

CVE-2015-4335 CRITICAL POC
10.0 Jun 09

Redis before 2.8.21 and 3.x before 3.0.2 allows remote attackers to execute arbitrary Lua bytecode via the eval command.

CVE-2016-8339 CRITICAL POC
9.8 Oct 28

A buffer overflow in Redis 3.2.x prior to 3.2.4 causes arbitrary code execution when a crafted command is sent. Rated cr

CVE-2026-77602 CRITICAL POC
9.9 Sep 23

Authenticated remote code execution in OpenC3 COSMOS (Ruby gem 'openc3' versions 5.1.0 through 7.2.1) lets any logged-in

CVE-2026-27574 CRITICAL POC
9.9 Feb 21

Code injection in OneUptime monitoring via custom JS monitor using vm module. PoC and patch available.

CVE-2026-84372 CRITICAL POC
9.8 Sep 01

RESP protocol command injection in Predis, the popular PHP client for Redis and Valkey, affects versions 3.0.0-RC1 throu

CVE-2021-31649 CRITICAL POC
9.8 Jun 24

In applications using jfinal 4.9.08 and below, there is a deserialization vulnerability when using redis,may be vulnerab

CVE-2020-11981 CRITICAL POC
9.8 Jul 17

An issue was found in Apache Airflow versions 1.10.10 and below. Rated critical severity (CVSS 9.8), this vulnerability

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy