VulnerabilityPublished 4 Nov 2026

CVE-2026-55098: Arc · DuckDB I/O aliases bypass database RBAC after CVE-2026-47735

Affects github.com/basekick-labs/arcSource GCVE Database

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Mentioned vulnerabilities

CVE-2026-47735

Authoritative record:CVE-2026-55098· Medium 6.5

Not known to be exploited · CVSS 6.5 Medium : upgrade to 0.0.0-20260610131716-5dc8f53b70a3 when convenient.

Data as of 4 Nov 2026, 18:30 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	6.5

Patch: Available – fixed in 0.0.0-20260610131716-5dc8f53b70a3

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 4 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade github.com/basekick-labs/arc to 0.0.0-20260610131716-5dc8f53b70a3.

Affected software

Product	Affected	Fixed in
Gogithub.com/basekick-labs/arc	Affected <0.0.0-20260610131716-5dc8f53b70a3	Fixed in 0.0.0-20260610131716-5dc8f53b70a3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available in Arc version 0.0.0-20260610131716-5dc8f53b70a3 that addresses this issue. The vendor recommends scoping the sandbox's allowed directories to the requesting token's authorized database path(s) to prevent cross-tenant file access. Alternatively, replacing the fragile function-name denylist with a strict allowlist of permitted table functions (resolving aliases) is advised. Users should upgrade to the fixed version to remediate this vulnerability.

Description

A vulnerability in Arc's integration with DuckDB allows any authenticated user, even with no permissions, to bypass database role-based access control (RBAC) and read data across all tenant databases within the shared storage root. The issue arises because the sandbox configuration permits access to the entire multi-tenant storage root, and the RBAC checks do not inspect table-valued functions such as DuckDB's I/O aliases (e.g., parquet_scan). Additionally, the SQL denylist only blocks the literal function read_parquet, missing other aliases and related functions. This enables cross-database data exposure despite RBAC enforcement.

Impact

Any authenticated user, including those with no assigned permissions, can bypass RBAC to read confidential data across all tenant databases stored under the shared storage root. This includes reading raw data files, enumerating database files, and accessing schema and column-level statistics. The SQLite token database is not exposed by this method. The impact is unauthorized cross-tenant data disclosure in RBAC-enabled deployments.

Summary

The fix for CVE-2026-47735 in Arc (released in version 26.06.1) introduced a sandbox restricting DuckDB external access to a configured storage root and a SQL denylist blocking the literal functions read_parquet and arc_partition_agg. However, the sandbox allowlists the entire multi-tenant storage root rather than scoping to individual tenant directories. RBAC enforcement skips table-valued functions, and the denylist only matches the literal read_parquet function, missing aliases like parquet_scan and other DuckDB I/O functions. Consequently, any authenticated token can execute queries using these unblocked functions to read or enumerate data files belonging to other databases within the shared storage root, bypassing RBAC. The vulnerability was confirmed on Arc version 26.06.1-36 (including 26.06.2) and DuckDB 1.5.x. The recommended remediation is to scope the sandbox allowed directories per authorized database or replace the denylist with a strict allowlist of permitted table functions.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-863Incorrect Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #17OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2026, 18:30 UTC

WeaknessesCWE-200, CWE-863

Technical details

References

Community reviews

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