VulnerabilityPublished 13 Aug 2026Updated 31 Oct 2026

CVE-2025-64429: Harlequin · DuckDB implemented block-based encryption of DB on the filesystem starting with DuckDB 1.4.0

Affects harlequinSource GCVE Database

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Not known to be exploited · CVSS 6.5 Medium : upgrade to 2.4.0 when convenient.

Data as of 31 Oct 2026, 16:51 UTC

CVSS 3.1 base score

6.5Medium

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

Patch: Available – fixed in 2.4.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 13 Aug 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 30 Oct 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 harlequin to 2.4.0.

Patches and advisories

github.com/duckdb/duckdb/pull/17275 (opens in a new tab)

Affected software

Product	Affected	Fixed in
Homebrewharlequin`pkg:brew/harlequin`Other threats	Affected >=2.3.0 <2.4.0	Fixed in 2.4.0

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

Description

DuckDB is a SQL database management system. DuckDB implemented block-based encryption of DB on the filesystem starting with DuckDB 1.4.0. There are a few issues related to this implementation. The DuckDB can fall back to an insecure random number generator (pcg32) to generate cryptographic keys or IVs. When clearing keys from memory, the compiler may remove the memset() and leave sensitive data on the heap. By modifying the database header, an attacker could downgrade the encryption mode from GCM to CTR to bypass integrity checks. There may be a failure to check return value on call to OpenSSL `rand_bytes()`. An attacker could use public IVs to compromise the internal state of RNG and determine the randomly generated key used to encrypt temporary files, get access to cryptographic keys if they have access to process memory (e.g. through memory leak),circumvent GCM integrity checks, and/or influence the OpenSSL random number generator and DuckDB would not be able to detect a failure of the generator. Version 1.4.2 has disabled the insecure random number generator by no longer using the fallback to write to or create databases. Instead, DuckDB will now attempt to install and load the OpenSSL implementation in the `httpfs` extension. DuckDB now uses secure MbedTLS primitive to clear memory as recommended and requires explicit specification of ciphers without integrity checks like CTR on `ATTACH`. Additionally, DuckDB now checks the return code.

References

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