ruby

5 tools · 4 release lines

Ruby programming language. Each tool carries its own sandbox boundary — they are not the same.

kapsl ruby

kapsl gem

kapsl bundle

kapsl rake

kapsl irb

Source ↗ Registry ↗

Release lines we maintain · the project decides these

findings shown are the whole project at that line

Tag Resolves to Lifecycle Updated Findings What the tag promises

latest 4.0.6 stable 2026-09-01

tracks the newest supported release 4.0 4.0.6 stable 2026-09-01

tracks the newest 4.0 release 3.4 3.4.10 stable 2026-09-01

tracks the newest 3.4 release 3.3 3.3.12 stable 2026-09-01

tracks the newest 3.3 release

stable — floats, carries security updates
unstable — tracks pre-releases, may break
eol — frozen, upstream is done

Tools in this project · pick one to inspect

capabilities differ between them

Tool Capabilities Seccomp Findings Image Description

ruby rw default

H2L1

H1L1

H1M2L1

ruby The Ruby programming language interpreter gem netrorw default

H2L1

H1L1

H1M2L1

ruby Package manager for Ruby bundle netrorw default

H2L1

H1L1

H1M2L1

ruby Ruby dependency manager driven by a Gemfile rake rw default

H2L1

H1L1

H1M2L1

ruby Ruby make-like build utility irb rw default

H2L1

H1L1

H1M2L1

ruby Interactive Ruby shell

showing ruby gem bundle rake irb from ruby@latest → 4.0.6 stable [email protected] → 4.0.6 stable [email protected] → 3.4.10 stable [email protected] → 3.3.12 stable

Findings

H2L1

identical on amd64, arm64 — one table describes both

CVE Sev CVSS Affects Description

CVE-2026-85091 ↗ H 8.3 zlib zlib versions 1.3.1.2 through 1.3.2 contain a heap buffer overflow vulnerability in the gz_vacate() function when processing non-blocking gzwrite() operations with stale external buffer pointers.

GHSA-3m6g-2423-7cp3 ↗ H 8.3 json Ruby JSON has a format string injection vulnerability

GHSA-x2f5-4prf-w687 ↗ L 3.7 json Ruby json: JSON generator heap buffer overflow when streaming to an IO

These are the findings of ruby, which ships every tool in this project. kapsl reports and gates; it never edits an image to clear a finding.

Findings

H2L1

identical on amd64, arm64 — one table describes both

CVE Sev CVSS Affects Description

GHSA-3m6g-2423-7cp3 ↗ H 8.3 json Ruby JSON has a format string injection vulnerability

GHSA-x2f5-4prf-w687 ↗ L 3.7 json Ruby json: JSON generator heap buffer overflow when streaming to an IO

These are the findings of ruby, which ships every tool in this project. kapsl reports and gates; it never edits an image to clear a finding.

Findings

H1L1

identical on amd64, arm64 — one table describes both

CVE Sev CVSS Affects Description

GHSA-x2f5-4prf-w687 ↗ L 3.7 json Ruby json: JSON generator heap buffer overflow when streaming to an IO

These are the findings of ruby, which ships every tool in this project. kapsl reports and gates; it never edits an image to clear a finding.

Findings

H1M2L1

identical on amd64, arm64 — one table describes both

CVE Sev CVSS Affects Description

ruby

capabilities

Filled is granted to every invocation; the rest need --cap at the point of use.

seccomp tier

per tool

default

The syscall filter applied to this tool's entry point. Tools sharing an image do not share a tier.

host paths mounted in

read-only unless noted

none

env passed through

7 forwarded

RUBYOPTRUBY_FREE_AT_EXITRUBY_GC_*RUBY_IO_BUFFER_DEFAULT_SIZERUBY_MAX_CPURUBY_MN_THREADSRUBY_THREAD_TIMESLICE

Nothing else crosses in. No AWS_*, no SSH_AUTH_SOCK unless you ask.

env set by kapsl

4 set

CPLUS_INCLUDE_PATHC_INCLUDE_PATHLIBRARY_PATHPKG_CONFIG_PATH

per-subcommand

no overrides

Every invocation gets the same boundary. Where a tool needs more for one subcommand only, kapsl scopes it there rather than granting it everywhere.

Sandbox boundary

gem

capabilities

netrorw

Filled is granted to every invocation, outlined to some and not others — see per-subcommand below; the rest need --cap at the point of use.

seccomp tier

per tool

default

The syscall filter applied to this tool's entry point. Tools sharing an image do not share a tier.

host paths mounted in

read-only unless noted

~/.gem · writable
~/.gemrc

env passed through

8 forwarded

GEM_HOST_API_KEYHTTPS_PROXYHTTP_PROXYNO_PROXYRUBYGEMS_HOSThttp_proxyhttps_proxyno_proxy

Nothing else crosses in. No AWS_*, no SSH_AUTH_SOCK unless you ask.

env set by kapsl

5 set

CPLUS_INCLUDE_PATHC_INCLUDE_PATHLIBRARY_PATHPKG_CONFIG_PATHRUBYGEMS_PREVENT_UPDATE_SUGGESTION

per-subcommand

narrower in places

build − net

check + ro − netrw

cleanup − net

config − net

mounts ~/.gemrc

contents + ro − netrw

environment + ro − netrw

help + ro − netrw

lock + ro − netrw

stale + ro − netrw

uninstall − net

unpack − net

which + ro − netrw

Where a tool needs more for one subcommand only, kapsl scopes it there rather than granting it everywhere. Where it needs less, kapsl takes it away there too.

Sandbox boundary

bundle

capabilities

netrorw

Filled is granted to every invocation, outlined to some and not others — see per-subcommand below; the rest need --cap at the point of use.

seccomp tier

per tool

default

The syscall filter applied to this tool's entry point. Tools sharing an image do not share a tier.

host paths mounted in

read-only unless noted

~/.bundle · writable
~/.gem · writable

env passed through

8 forwarded

BUNDLE_*GEM_HOST_API_KEYHTTPS_PROXYHTTP_PROXYNO_PROXYhttp_proxyhttps_proxyno_proxy

Nothing else crosses in. No AWS_*, no SSH_AUTH_SOCK unless you ask.

env set by kapsl

5 set

CPLUS_INCLUDE_PATHC_INCLUDE_PATHLIBRARY_PATHPKG_CONFIG_PATHRUBYGEMS_PREVENT_UPDATE_SUGGESTION

per-subcommand

narrower in places

check + ro − netrw

list + ro − netrw

show + ro − netrw

version + ro − netrw

Where a tool needs more for one subcommand only, kapsl scopes it there rather than granting it everywhere. Where it needs less, kapsl takes it away there too.