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EPSS 0.4%top 67%

CVE-2026-9521: Improper Validation of Specified Type of Input in fraillt bitsery

0
Medium
VulnerabilityCVE-2026-9521cvecve-2026-9521
Published: 05/26/2026 (05/26/2026, 02:00:15 UTC)
Source: CVE Database V5
Vendor/Project: fraillt
Product: bitsery

Description

A security vulnerability has been detected in fraillt bitsery up to 5.2.4. Affected is the function loadFromSharedState in the library include/bitsery/ext/std_smart_ptr.h. Such manipulation leads to improper validation of specified type of input. It is possible to launch the attack remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 5.2.5 is able to address this issue. The name of the patch is 66d16516e24893bebc1c8af52bf2fe9ad0735061. Upgrading the affected component is advised.

CVSS v4.0

Score 6.3medium

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Vuln. Confidentiality
Low
Vuln. Integrity
Low
Vuln. Availability
Low
Subsq. Confidentiality
None
Subsq. Integrity
None
Subsq. Availability
None
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Affected software

GitHub Actionsmore threats →ai
fraillt/bitsery
pkg:github/fraillt/bitsery
Affected versions
=5.2.0=5.2.1=5.2.2=5.2.3=5.2.4

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AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 05/26/2026, 02:24:52 UTC

Technical Analysis

The fraillt bitsery library up to version 5.2.4 contains a vulnerability in the loadFromSharedState function of std_smart_ptr.h that allows improper validation of input types. This flaw can be triggered remotely, potentially leading to unexpected behavior or security risks. The vulnerability is fixed in version 5.2.5 with patch 66d16516e24893bebc1c8af52bf2fe9ad0735061.

Potential Impact

The vulnerability allows remote attackers to manipulate input types improperly validated by the loadFromSharedState function, which could lead to security issues such as data corruption or other unintended effects. The CVSS 4.0 base score is 6.3 (medium severity), indicating a moderate impact with network attack vector, low complexity, no privileges required, and no user interaction needed.

Mitigation Recommendations

Upgrade the fraillt bitsery library to version 5.2.5 or later, which contains the official fix for this vulnerability (patch 66d16516e24893bebc1c8af52bf2fe9ad0735061). No other mitigation steps are indicated by the vendor advisory.

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Technical Details

Data Version
5.2
Assigner Short Name
VulDB
Date Reserved
2026-05-25T19:17:31.511Z
Cvss Version
4.0
State
PUBLISHED
Remediation Level
null

Threat ID: 6a1500ffa5ae1af1aa1c8a44

Added to database: 05/26/2026, 02:10:07 UTC

Last enriched: 05/26/2026, 02:24:52 UTC

Last updated: 07/31/2026, 19:23:00 UTC

Views: 101

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