UBUNTU-CVE-2026-56389

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Source
https://ubuntu.com/security/CVE-2026-56389
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-56389.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-56389
Upstream
  • CVE-2026-56389
Published
2026-07-30T00:00:00Z
Modified
2026-07-30T16:00:27.473028920Z
Severity
  • 6.8 (Medium) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/SC:L/SI:L/SA:L CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

GNU Bison allows for an execution of an arbitrary program during HTML report generation due to improper handling of grammar-defined configuration variables. A grammar file can override the executable used for the XML‑to‑HTML transformation step via %define tool.xsltproc, which is accepted without restriction and passed directly to execvp(). When running bison --html on a attacker-provided grammar, this behavior allows execution of an arbitrary program with the privileges of the Bison process. Maintainers of this project were notified about this vulnerability, and fixed the issue in commit 3169c1e7a2c6acc4c59dfcf8b089896d6881925b. 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-2026-56389.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-2026-56389.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-2026-56389.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-2026-56389.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-2026-56389.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-2026-56389.json"