CVE-2026-44983
Deferred Deferred - Pending Action
Integer Overflow Leading to Heap Buffer Overflow in smallbitvec

Publication date: 2026-05-26

Last updated on: 2026-06-01

Assigner: GitHub, Inc.

Description
smallbitvec is a growable bit-vector for Rust, optimized for size. From 1.0.1 to 2.6.0, an integer overflow in the internal capacity calculation of smallbitvec can lead to an undersized heap allocation, resulting in a heap buffer overflow through safe APIs only. This allows memory corruption without requiring unsafe code from the caller. This vulnerability is fixed in 2.6.1.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-05-26
Last Modified
2026-06-01
Generated
2026-06-16
AI Q&A
2026-05-27
EPSS Evaluated
2026-06-14
NVD
CVE-2026-44983
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
smallbitvec smallbitvec to 2.6.0 (inc)
smallbitvec smallbitvec 2.6.1
smallbitvec smallbitvec From 1.0.1 (inc) to 2.6.1 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-190 The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
CWE-122 A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

The vulnerability exists in the smallbitvec Rust library versions 1.0.1 to 2.6.0. It is caused by an integer overflow in the internal capacity calculation, which leads to an undersized heap allocation. This results in a heap buffer overflow that can be triggered through safe APIs without requiring the caller to use unsafe code.

Impact Analysis

This vulnerability can lead to memory corruption due to a heap buffer overflow. Such memory corruption can cause application crashes, data corruption, or potentially allow an attacker to execute arbitrary code or escalate privileges, depending on the context in which the library is used.

Mitigation Strategies

To mitigate this vulnerability, you should upgrade the smallbitvec library to version 2.6.1 or later, where the integer overflow and resulting heap buffer overflow have been fixed.

Avoid using versions from 1.0.1 to 2.6.0, as they are vulnerable to this issue.

Compliance Impact

The vulnerability in smallbitvec can lead to heap buffer overflow causing memory corruption, which potentially impacts confidentiality, integrity, and availability of data.

Such impacts on data security could affect compliance with common standards and regulations like GDPR and HIPAA, which require protection of sensitive data and maintaining system integrity and availability.

However, the provided information does not explicitly mention compliance implications or specific regulatory impacts.

Detection Guidance

This vulnerability in smallbitvec can be detected using dynamic analysis tools such as AddressSanitizer (ASAN) and Miri. These tools can reveal heap-buffer-overflow and undefined behavior caused by the integer overflow and subsequent heap corruption.

Since the vulnerability is triggered by integer overflow in capacity calculations leading to heap buffer overflow, running tests or applications that use smallbitvec with ASAN or Miri enabled can help detect the issue.

There are no specific network detection commands because the attack vector is local and involves memory corruption within the Rust crate.

Suggested commands include running your Rust tests or binaries with AddressSanitizer enabled, for example:

  • Set environment variable for ASAN: `export RUSTFLAGS='-Z sanitizer=address'`
  • Run tests with cargo: `cargo +nightly test`
  • Alternatively, run with Miri to detect undefined behavior: `cargo +nightly miri test`

These commands help detect heap buffer overflows and integer overflow issues in Rust code using smallbitvec versions 1.0.1 through 2.6.0.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-44983. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart