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CRITICAL severity

CVE-2019-16139 — compact_arena

CRITICAL

CVE-2019-16139 is a critical-severity (CVSS 9.8) Out-of-bounds Read vulnerability in compact_arena. A fix is available for compact_arena — see the affected versions and patch details below.

Out of bounds access in compact_arena

Also known asRUSTSEC-2019-0015
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.9%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs79th percentile — riskier than 79% of all scored CVEsHighest risk
0.00%0.79%1.57%2.35%0.4%1.9%Apr 26Aug 26Oct 26

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

How urgent is this, really

CVE-2019-16139 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected
🦀compact_arena

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

Affected versions of this crate did not properly implement the generativity, because the invariant lifetimes were not necessarily dropped.

This allows an attacker to mix up two arenas, using indices created from one arena with another one. This might lead to an out-of-bounds read or write access into the memory reserved for the arena.

The flaw was corrected by implementing generativity correctly in version 0.4.0.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.iocompact_arenaall versions0.4.0cargo update -p compact_arena --precise 0.4.0

Affected Products

1 product · 1 configurations
Application
compact arenacompact_arena_project
< 0.4.0
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for compact_arena, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update compact_arena to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-16139 is resolved across your whole dependency graph.

  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.

Frequently Asked Questions

Affected versions of this crate did not properly implement the generativity, because the invariant lifetimes were not necessarily dropped. This allows an attacker to mix up two arenas, using indices created from one arena with another one. This might lead to an out-of-bounds read or write access into the memory reserved for the arena. The flaw was corrected by implementing generativity correctly in version 0.4.0.
O3 Security · Impact-Aware SCA

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CVE-2019-16139: compact_arena — Fixed in 0.4.0