Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-54786— Wasmtime: Leak in WASIp1 `fd_renumber` implementation

Quick assessment

Affected
bytecodealliance wasmtime
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Bytecode Alliance wasmtime是Bytecode Alliance基金会开源的一个轻量级WebAssembly运行时。 Bytecode Alliance wasmtime存在资源管理错误漏洞，该漏洞源于WASIp1原生实现中fd_renumber函数对文件描述符未正确关闭，导致资源泄露，可能造成主机资源耗尽。以下版本受到影响：24.0.10之前版本、25.0.0至36.0.11之前版本、37.0.0至44.0.3之前版本、45.0.0版本和45.0.1版本。

AI Predicted 7.5 Difficulty: Easy EPSS 0.37% · P28

Possible ATT&CK Techniques 1 AI

T1496 · Resource Hijacking

Affected Version Matrix 4

VendorProduct Version RangeStatus
bytecodealliance wasmtime < 24.0.10 affected
>= 25.0.0, < 36.0.11 affected
>= 37.0.0, < 44.0.3 affected
>= 45.0.0, < 45.0.2 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-54786

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Wasmtime: Leak in WASIp1 `fd_renumber` implementation
Source: CVE Program / CVE List V5
Vulnerability Description
Wasmtime is a runtime for WebAssembly. All versions prior to 24.0.10; versions 25.0.0 through those before 36.0.11; versions 37.0.0 through those before 44.0.3; and versions 45.0.0 and 45.0.1 contain a native implementation of WASIp1 which suffers from a leak in the fd_renumber function where the file descriptor being renumbered to is not properly closed. Wasmtime's implementation erroneously only updated the table of descriptors for WASIp1 and didn't update the underlying table of descriptors used by the host. This behavior means that while fd_renumber works correctly from a guest's perspective it ends up leaking resources in the host that aren't cleaned up until the corresponding Store is destroyed. In a loop, guests can use fd_renumber to cause hosts to exhaust both resources and file descriptors. This bug only affects the native implementation of WASIp1, meaning that only runtimes which load core wasm modules and expose fd_renumber are affected. Runtimes are additionally only affected if they expose the ability to acquire a file descriptor, such as opening a file. For runtimes that deny access to files they are unaffected. This issue has been fixed in versions 24.0.10, 36.0.11, 44.0.3, and 45.0.2.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L
Source: CVE Program / CVE List V5
Vulnerability Type
对已超过有效生命周期的资源丧失索引
Source: CVE Program / CVE List V5
Vulnerability Title
Bytecode Alliance wasmtime 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Bytecode Alliance wasmtime是Bytecode Alliance基金会开源的一个轻量级WebAssembly运行时。 Bytecode Alliance wasmtime存在资源管理错误漏洞，该漏洞源于WASIp1原生实现中fd_renumber函数对文件描述符未正确关闭，导致资源泄露，可能造成主机资源耗尽。以下版本受到影响：24.0.10之前版本、25.0.0至36.0.11之前版本、37.0.0至44.0.3之前版本、45.0.0版本和45.0.1版本。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
bytecodealliance wasmtime < 24.0.10 -

II. Public POCs for CVE-2026-54786

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-54786

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-54786 (1)

IV. Related Vulnerabilities

Same product: wasmtime
Same vendor: bytecodealliance
Same weakness: CWE-772

V. Comments for CVE-2026-54786

No comments yet

Leave a comment