UBUNTU-CVE-2026-82455 (CVE-2026-82455)
Vulnerability from osv_ubuntu – Published: 2026-08-29 14:16 – Updated: 2026-09-02 16:28 – Source website
Withdrawn 2026-09-16
VLAI
Details
RubyGems fails to re-validate path containment after filesystem symlink resolution during gem extraction. When a pre-existing symlink inside the destination directory points outside the extraction root, extracted files that appear to be written under the destination directory can instead be written outside of it, breaking the extraction safety boundary. The fix resolves the real path of the parent directory before writing and raises Gem::Package::PathError if it escapes the destination directory.
Severity
7.1 (High)
N/A (UNKNOWN)
References
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "jruby",
"binary_version": "1.5.6-9+deb8u2build0.14.04.1~esm2"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:14.04:LTS",
"name": "jruby",
"purl": "pkg:deb/ubuntu/jruby@1.5.6-9+deb8u2build0.14.04.1~esm2?arch=source\u0026distro=esm-infra-legacy/trusty"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.5.6-5ubuntu1",
"1.5.6-6",
"1.5.6-7",
"1.5.6-9+deb8u2build0.14.04.1~esm2"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libruby2.3",
"binary_version": "2.3.1-2~ubuntu16.04.16+esm15"
},
{
"binary_name": "ruby2.3",
"binary_version": "2.3.1-2~ubuntu16.04.16+esm15"
},
{
"binary_name": "ruby2.3-tcltk",
"binary_version": "2.3.1-2~ubuntu16.04.16+esm15"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:16.04:LTS",
"name": "ruby2.3",
"purl": "pkg:deb/ubuntu/ruby2.3@2.3.1-2~ubuntu16.04.16+esm15?arch=source\u0026distro=esm-infra-legacy/xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.3.0-1",
"2.3.0-2",
"2.3.0-4ubuntu2",
"2.3.0-4ubuntu3",
"2.3.0-5ubuntu1",
"2.3.1-2~16.04",
"2.3.1-2~16.04.2",
"2.3.1-2~16.04.4",
"2.3.1-2~16.04.5",
"2.3.1-2~16.04.6",
"2.3.1-2~16.04.7",
"2.3.1-2~16.04.9",
"2.3.1-2~16.04.10",
"2.3.1-2~16.04.11",
"2.3.1-2~16.04.12",
"2.3.1-2~ubuntu16.04.13",
"2.3.1-2~ubuntu16.04.14",
"2.3.1-2~ubuntu16.04.15",
"2.3.1-2~ubuntu16.04.16",
"2.3.1-2~ubuntu16.04.16+esm1",
"2.3.1-2~ubuntu16.04.16+esm2",
"2.3.1-2~ubuntu16.04.16+esm3",
"2.3.1-2~ubuntu16.04.16+esm4",
"2.3.1-2~ubuntu16.04.16+esm5",
"2.3.1-2~ubuntu16.04.16+esm6",
"2.3.1-2~ubuntu16.04.16+esm7",
"2.3.1-2~ubuntu16.04.16+esm8",
"2.3.1-2~ubuntu16.04.16+esm9",
"2.3.1-2~ubuntu16.04.16+esm10",
"2.3.1-2~ubuntu16.04.16+esm11",
"2.3.1-2~ubuntu16.04.16+esm12",
"2.3.1-2~ubuntu16.04.16+esm14",
"2.3.1-2~ubuntu16.04.16+esm15"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "jruby",
"binary_version": "1.7.22-1ubuntu1"
}
]
},
"package": {
"ecosystem": "Ubuntu:16.04:LTS",
"name": "jruby",
"purl": "pkg:deb/ubuntu/jruby@1.7.22-1ubuntu1?arch=source\u0026distro=xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.7.21-2ubuntu4",
"1.7.22-1ubuntu1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libruby2.5",
"binary_version": "2.5.1-1ubuntu1.16+esm8"
},
{
"binary_name": "ruby2.5",
"binary_version": "2.5.1-1ubuntu1.16+esm8"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:18.04:LTS",
"name": "ruby2.5",
"purl": "pkg:deb/ubuntu/ruby2.5@2.5.1-1ubuntu1.16+esm8?arch=source\u0026distro=esm-infra/bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.5.0~preview1-1ubuntu2",
"2.5.0-4ubuntu1",
"2.5.0-4ubuntu4",
"2.5.0-5ubuntu1",
"2.5.0-6ubuntu1",
"2.5.1-1ubuntu1",
"2.5.1-1ubuntu1.1",
"2.5.1-1ubuntu1.2",
"2.5.1-1ubuntu1.4",
"2.5.1-1ubuntu1.5",
"2.5.1-1ubuntu1.6",
"2.5.1-1ubuntu1.7",
"2.5.1-1ubuntu1.8",
"2.5.1-1ubuntu1.9",
"2.5.1-1ubuntu1.10",
"2.5.1-1ubuntu1.11",
"2.5.1-1ubuntu1.12",
"2.5.1-1ubuntu1.13",
"2.5.1-1ubuntu1.14",
"2.5.1-1ubuntu1.15",
"2.5.1-1ubuntu1.16",
"2.5.1-1ubuntu1.16+esm1",
"2.5.1-1ubuntu1.16+esm3",
"2.5.1-1ubuntu1.16+esm4",
"2.5.1-1ubuntu1.16+esm5",
"2.5.1-1ubuntu1.16+esm6",
"2.5.1-1ubuntu1.16+esm7",
"2.5.1-1ubuntu1.16+esm8"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "jruby",
"binary_version": "9.1.17.0-1~18.04"
}
]
},
"package": {
"ecosystem": "Ubuntu:18.04:LTS",
"name": "jruby",
"purl": "pkg:deb/ubuntu/jruby@9.1.17.0-1~18.04?arch=source\u0026distro=bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"9.1.13.0-1",
"9.1.17.0-1~18.04"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libruby2.7",
"binary_version": "2.7.0-5ubuntu1.18+esm5"
},
{
"binary_name": "ruby2.7",
"binary_version": "2.7.0-5ubuntu1.18+esm5"
}
]
},
"package": {
"ecosystem": "Ubuntu:Pro:20.04:LTS",
"name": "ruby2.7",
"purl": "pkg:deb/ubuntu/ruby2.7@2.7.0-5ubuntu1.18+esm5?arch=source\u0026distro=esm-infra/focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"2.7.0-1",
"2.7.0-2",
"2.7.0-3",
"2.7.0-4",
"2.7.0-4ubuntu1",
"2.7.0-5ubuntu1",
"2.7.0-5ubuntu1.1",
"2.7.0-5ubuntu1.2",
"2.7.0-5ubuntu1.3",
"2.7.0-5ubuntu1.4",
"2.7.0-5ubuntu1.5",
"2.7.0-5ubuntu1.6",
"2.7.0-5ubuntu1.7",
"2.7.0-5ubuntu1.8",
"2.7.0-5ubuntu1.9",
"2.7.0-5ubuntu1.10",
"2.7.0-5ubuntu1.11",
"2.7.0-5ubuntu1.12",
"2.7.0-5ubuntu1.13",
"2.7.0-5ubuntu1.14",
"2.7.0-5ubuntu1.15",
"2.7.0-5ubuntu1.16",
"2.7.0-5ubuntu1.17",
"2.7.0-5ubuntu1.18",
"2.7.0-5ubuntu1.18+esm1",
"2.7.0-5ubuntu1.18+esm3",
"2.7.0-5ubuntu1.18+esm4",
"2.7.0-5ubuntu1.18+esm5"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "jruby",
"binary_version": "9.1.17.0-3build6"
}
]
},
"package": {
"ecosystem": "Ubuntu:20.04:LTS",
"name": "jruby",
"purl": "pkg:deb/ubuntu/jruby@9.1.17.0-3build6?arch=source\u0026distro=focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"9.1.17.0-3",
"9.1.17.0-3build5",
"9.1.17.0-3build6"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libruby3.0",
"binary_version": "3.0.2-7ubuntu2.13"
},
{
"binary_name": "ruby3.0",
"binary_version": "3.0.2-7ubuntu2.13"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "ruby3.0",
"purl": "pkg:deb/ubuntu/ruby3.0@3.0.2-7ubuntu2.13?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"3.0.2-5ubuntu1",
"3.0.2-7",
"3.0.2-7ubuntu2",
"3.0.2-7ubuntu2.1",
"3.0.2-7ubuntu2.2",
"3.0.2-7ubuntu2.3",
"3.0.2-7ubuntu2.4",
"3.0.2-7ubuntu2.5",
"3.0.2-7ubuntu2.6",
"3.0.2-7ubuntu2.7",
"3.0.2-7ubuntu2.8",
"3.0.2-7ubuntu2.10",
"3.0.2-7ubuntu2.11",
"3.0.2-7ubuntu2.12",
"3.0.2-7ubuntu2.13"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "bundler",
"binary_version": "2.3.5-2ubuntu1.2"
},
{
"binary_name": "ruby-bundler",
"binary_version": "2.3.5-2ubuntu1.2"
},
{
"binary_name": "ruby-rubygems",
"binary_version": "3.3.5-2ubuntu1.2"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "rubygems",
"purl": "pkg:deb/ubuntu/rubygems@3.3.5-2ubuntu1.2?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"3.2.5-2",
"3.2.27-2",
"3.2.27-3",
"3.3.5-2",
"3.3.5-2ubuntu1.1",
"3.3.5-2ubuntu1.2"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "jruby",
"binary_version": "9.4.6.0+ds-1ubuntu3"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "jruby",
"purl": "pkg:deb/ubuntu/jruby@9.4.6.0+ds-1ubuntu3?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"9.3.9.0+ds-1",
"9.4.5.0+ds-1",
"9.4.5.0+ds-1ubuntu1",
"9.4.6.0+ds-1ubuntu3"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "bundler",
"binary_version": "2.4.20-1"
},
{
"binary_name": "ruby-bundler",
"binary_version": "2.4.20-1"
},
{
"binary_name": "ruby-rubygems",
"binary_version": "3.4.20-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "rubygems",
"purl": "pkg:deb/ubuntu/rubygems@3.4.20-1?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"3.3.15-2",
"3.4.20-1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "jruby",
"binary_version": "9.4.8.0+ds-3ubuntu1"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "jruby",
"purl": "pkg:deb/ubuntu/jruby@9.4.8.0+ds-3ubuntu1?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"9.4.8.0+ds-3ubuntu1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "bundler",
"binary_version": "2.6.7-2ubuntu2"
},
{
"binary_name": "ruby-bundler",
"binary_version": "2.6.7-2ubuntu2"
},
{
"binary_name": "ruby-rubygems",
"binary_version": "3.6.7-2ubuntu2"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "rubygems",
"purl": "pkg:deb/ubuntu/rubygems@3.6.7-2ubuntu2?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"3.6.7-2ubuntu1",
"3.6.7-2ubuntu2"
]
}
],
"aliases": [],
"details": "RubyGems fails to re-validate path containment after filesystem symlink resolution during gem extraction. When a pre-existing symlink inside the destination directory points outside the extraction root, extracted files that appear to be written under the destination directory can instead be written outside of it, breaking the extraction safety boundary. The fix resolves the real path of the parent directory before writing and raises Gem::Package::PathError if it escapes the destination directory.",
"id": "UBUNTU-CVE-2026-82455",
"modified": "2026-09-02T16:28:28Z",
"published": "2026-08-29T14:16:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-82455"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-82455"
},
{
"type": "REPORT",
"url": "https://github.com/ruby/rubygems/pull/9493"
},
{
"type": "REPORT",
"url": "https://github.com/ruby/rubygems"
},
{
"type": "REPORT",
"url": "https://github.com/ruby/rubygems/commit/103ca4230deacb31b9fcd813de109e83b5fc71ac"
},
{
"type": "REPORT",
"url": "https://www.vulncheck.com/advisories/rubygems-before-4.0.13-path-traversal-via-symlink-resolution"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2026-82455"
],
"withdrawn": "2026-09-16T11:43:09Z"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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