Bytecode Alliance Wasmtime up to 36.0.16/48.0.3/49.0.1 Wasi P1 fd_readdir information disclosure

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.0$0-$5k0.41

Summaryinfo

A vulnerability was found in Bytecode Alliance Wasmtime up to 36.0.16/48.0.3/49.0.1 and classified as problematic. Affected by this vulnerability is the function fd_readdir of the component Wasi P1. The manipulation results in information disclosure. This vulnerability is identified as CVE-2026-115386. The attack can be executed remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Bytecode Alliance Wasmtime up to 36.0.16/48.0.3/49.0.1. It has been classified as problematic. Affected is the function fd_readdir of the component Wasi P1. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. CVE summarizes:

Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an information disclosure vulnerability in the WASIp1 fd_readdir implementation that copies uninitialized struct padding into guest memory. Guests with a preopened directory can list entries to receive three bytes of leftover host stack or heap memory per directory entry.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-115386 since 10/22/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1592.

Upgrading to version 36.0.17, 48.0.4 or 49.0.2 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Name

Version

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: 3.1
VulDB Meta Temp Score: 3.0

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 2.6
CNA Vector (VulnCheck): 🔒

CVSSv2info

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

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
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: Wasmtime 36.0.17/48.0.4/49.0.2

Timelineinfo

10/22/2026 Advisory disclosed
10/22/2026 +0 days CVE reserved
10/22/2026 +0 days VulDB entry created
10/22/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-115386 (🔒)
GCVE (CVE): GCVE-0-2026-115386
GCVE (VulDB): GCVE-100-425436

Entryinfo

Created: 10/22/2026 22:18
Changes: 10/22/2026 22:18 (77)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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