sveltejs devalue up to 5.9.2 uneval memory allocation

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00+

Summaryinfo

A vulnerability labeled as problematic has been found in sveltejs devalue up to 5.9.2. The impacted element is the function uneval. Executing a manipulation can lead to memory allocation. This vulnerability is handled as CVE-2026-123564. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in sveltejs devalue up to 5.9.2. It has been declared as problematic. This vulnerability affects the function uneval. The manipulation with an unknown input leads to a memory allocation vulnerability. The CWE definition for the vulnerability is CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. As an impact it is known to affect availability. CVE summarizes:

Sveltejs devalue from 1.0.0 before 5.9.3 contains a memory exhaustion flaw in uneval, whose generated code for sparse arrays allocates memory proportional to the array's declared length when evaluated. Attackers who can influence a very large sparse array serialized by an application can exhaust memory in the browser or runtime evaluating the output.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-123564 since 11/06/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

Upgrading to version 5.9.3 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory allocation
CWE: CWE-789 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: devalue 5.9.3

Timelineinfo

11/06/2026 CVE reserved
11/08/2026 +2 days Advisory disclosed
11/08/2026 +0 days VulDB entry created
11/08/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CNA: VulnCheck
CVE: CVE-2026-123564 (🔒)

GCVE (CVE): GCVE-0-2026-123564
GCVE (VulDB): GCVE-100-432736

Entryinfo

Created: 11/08/2026 03:24
Changes: 11/08/2026 03:24 (76)
Complete: 🔍
Cache ID: 216::103

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