Skip to content

rust-zserio has Unbounded Memory Allocation

High severity GitHub Reviewed Published May 1, 2026 in Danaozhong/rust-zserio • Updated May 7, 2026

Package

cargo rust-zserio (Rust)

Affected versions

<= 0.5.3

Patched versions

0.5.4

Description

Impact

When deserializing arrays, strings or bytes (blob) types zserio first reads the size of the variable, and then allocates sufficient memory to load data. Since the size is always trusted this can be abused by creating a data file with a large size value, causing the zserio runtime to allocate large amounts of memory.

Patches

Please cherry-pick 57f5fb.

Workarounds

  • Do not accept zserio-encoded messages from non-trusted sources.
  • Allocate a maximum heap amount to rust-zerio to avoid impacting other applications.

References

@Danaozhong Danaozhong published to Danaozhong/rust-zserio May 1, 2026
Published to the GitHub Advisory Database May 7, 2026
Reviewed May 7, 2026
Last updated May 7, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

Weaknesses

Memory Allocation with Excessive Size Value

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. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-fpf5-4jw8-67x8
Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.