CVE-2021-31919Network attack vector

Process-memory disclosure via uninitialized archive bytes

Published Apr 30, 2021 · Updated Aug 3, 2024

Information disclosure in the rkyv crate before 0.6.0 allows remote attackers to read process memory through serialized archives. Archive::resolve writes complete struct-compatible memory into an archive without ensuring that struct padding and unused enum bytes are initialized. Exposure occurs when an application serializes affected types and stores the archive or sends it over an unsecured channel, disclosing residual bytes occupying those gaps.

CVSS severity7.5
High
EPSS probability1.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in the rkyv crate before 0.6.0 allows remote attackers to read process memory through serialized archives. Archive::resolve writes complete struct-compatible memory into an archive without ensuring that struct padding and unused enum bytes are initialized. Exposure occurs when an application serializes affected types and stores the archive or sends it over an unsecured channel, disclosing residual bytes occupying those gaps.

The record

CVE
CVE-2021-31919
Published
Apr 30, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-772, CWE-908
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5RustSec Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-772Missing Release of Resource after Effective Lifetime
CWE-908Use of Uninitialized Resource

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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