UBUNTU-CVE-2026-56390

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Source
https://ubuntu.com/security/CVE-2026-56390
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56390.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-56390
Upstream
  • CVE-2026-56390
Published
2026-07-30T00:00:00Z
Modified
2026-07-30T16:00:27.520371968Z
Severity
  • 4.6 (Medium) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

GNU Bison improperly handles grammar‑defined output paths. Grammar directives such as %output and %header allow specifying file paths, which are accepted without restriction and override caller‑supplied output options. When processing attacker-supplied grammar, this behavior allows directing generated files to arbitrary writable locations on the filesystem, potentially overwriting existing files accessible to the Bison process. Maintainers of this project were notified about this vulnerability, and fixed the issue in commit 8d101c19d4d9aaedf83a448c925513742d4efcf0. However, they did not provide vulnerable version range. Version 3.8.2 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.

References

Affected packages

Ubuntu:16.04:LTS
bison

Package

Name
bison
Purl
pkg:deb/ubuntu/bison?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2:3.*
2:3.0.2.dfsg-2
2:3.0.4.dfsg-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "bison",
            "binary_version": "2:3.0.4.dfsg-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56390.json"
Ubuntu:18.04:LTS
bison

Package

Name
bison
Purl
pkg:deb/ubuntu/bison?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2:3.*
2:3.0.4.dfsg-1build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "bison",
            "binary_version": "2:3.0.4.dfsg-1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56390.json"
Ubuntu:20.04:LTS
bison

Package

Name
bison
Purl
pkg:deb/ubuntu/bison?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2:3.*
2:3.4.1+dfsg-4
2:3.4.2+dfsg-1
2:3.5.1+dfsg-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "bison",
            "binary_version": "2:3.5.1+dfsg-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56390.json"
Ubuntu:22.04:LTS
bison

Package

Name
bison
Purl
pkg:deb/ubuntu/bison?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2:3.*
2:3.7.6+dfsg-1build1
2:3.8.2+dfsg-1
2:3.8.2+dfsg-1build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "bison",
            "binary_version": "2:3.8.2+dfsg-1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56390.json"
Ubuntu:24.04:LTS
bison

Package

Name
bison
Purl
pkg:deb/ubuntu/bison?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2:3.*
2:3.8.2+dfsg-1build1
2:3.8.2+dfsg-1build2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "bison",
            "binary_version": "2:3.8.2+dfsg-1build2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56390.json"
Ubuntu:26.04:LTS
bison

Package

Name
bison
Purl
pkg:deb/ubuntu/bison?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2:3.*
2:3.8.2+dfsg-1build3
2:3.8.2+dfsg-1build4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "bison",
            "binary_version": "2:3.8.2+dfsg-1build4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56390.json"