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CRITICAL severity

CVE-2021-28034 — Stack Dst

CRITICAL

CVE-2021-28034 is a critical-severity (CVSS 9.8) CWE-415 vulnerability in stack_dst_project stack dst. A fix is available — see the affected versions and patch details below.

An issue was discovered in the stack_dst crate before 0.6.1 for Rust. Because of the push_inner behavior, a double free can occur upon a val.clone() panic.

Published
Updated
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs69th percentile — riskier than 69% of all scored CVEsHighest risk
0.00%0.60%1.20%1.80%0.4%1.3%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-28034 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

An issue was discovered in the stack_dst crate before 0.6.1 for Rust. Because of the push_inner behavior, a double free can occur upon a val.clone() panic.

Affected Products

1 product · 1 configurations
Application
stack dststack_dst_project
< 0.6.1
range

Detection & mitigation playbook

Vendor / appliance

  1. Detect

    Inventory every stack_dst_project stack dst deployment and check each version against the affected-products list above.

  2. Fix

    Apply the stack_dst_project stack dst security patch or hotfix for CVE-2021-28034 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

An issue was discovered in the stack_dst crate before 0.6.1 for Rust. Because of the push_inner behavior, a double free can occur upon a val.clone() panic.
O3 Security · Runtime Protection

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CVE-2021-28034: Stack Dst (Critical 9.8)