UBUNTU-CVE-2026-73639 (CVE-2026-73639)
Vulnerability from osv_ubuntu – Published: 2026-09-17 22:17 – Updated: 2026-09-23 23:34 – Source websiteImager::File::PNG versions from 1.003 before 1.004 for Perl write past the end of the row buffer reading a PNG with a tRNS transparency chunk in read_direct8. With a tRNS chunk, read_direct8() adds an alpha channel to the image it creates but still sizes the row buffer from the original channel count. libpng expands the transparency into that extra channel, so png_read_row() fills one channel more than the buffer holds, at one byte per sample, and writes width bytes past the end of the allocation. Palette images go to read_paletted() and 16-bit images to read_direct16(), which sizes its buffer from png_get_rowbytes() and allocates enough for the expanded row. The same reader ships bundled in the Imager distribution. Reading an attacker-supplied PNG through Imager->read() corrupts the heap, which can crash the process.
{
"affected": [
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libimager-perl",
"binary_version": "1.004+dfsg-1build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:16.04:LTS",
"name": "libimager-perl",
"purl": "pkg:deb/ubuntu/libimager-perl@1.004+dfsg-1build1?arch=source\u0026distro=xenial"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.003+dfsg-1",
"1.004+dfsg-1",
"1.004+dfsg-1build1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libimager-perl",
"binary_version": "1.006+dfsg-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:18.04:LTS",
"name": "libimager-perl",
"purl": "pkg:deb/ubuntu/libimager-perl@1.006+dfsg-1?arch=source\u0026distro=bionic"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.005+dfsg-2build1",
"1.006+dfsg-1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libimager-perl",
"binary_version": "1.011+dfsg-1build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:20.04:LTS",
"name": "libimager-perl",
"purl": "pkg:deb/ubuntu/libimager-perl@1.011+dfsg-1build1?arch=source\u0026distro=focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.011+dfsg-1",
"1.011+dfsg-1build1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libimager-perl",
"binary_version": "1.012+dfsg-2build1"
}
]
},
"package": {
"ecosystem": "Ubuntu:22.04:LTS",
"name": "libimager-perl",
"purl": "pkg:deb/ubuntu/libimager-perl@1.012+dfsg-2build1?arch=source\u0026distro=jammy"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.012+dfsg-1build1",
"1.012+dfsg-2",
"1.012+dfsg-2build1"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libimager-perl",
"binary_version": "1.023+dfsg-1build2"
}
]
},
"package": {
"ecosystem": "Ubuntu:24.04:LTS",
"name": "libimager-perl",
"purl": "pkg:deb/ubuntu/libimager-perl@1.023+dfsg-1build2?arch=source\u0026distro=noble"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.019+dfsg-2",
"1.020+dfsg-1",
"1.022+dfsg-1",
"1.023+dfsg-1",
"1.023+dfsg-1build1",
"1.023+dfsg-1build2"
]
},
{
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libimager-perl",
"binary_version": "1.029+dfsg-1"
}
]
},
"package": {
"ecosystem": "Ubuntu:26.04:LTS",
"name": "libimager-perl",
"purl": "pkg:deb/ubuntu/libimager-perl@1.029+dfsg-1?arch=source\u0026distro=resolute"
},
"ranges": [
{
"events": [
{
"introduced": "0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.027+dfsg-1",
"1.029+dfsg-1"
]
}
],
"aliases": [],
"details": "Imager::File::PNG versions from 1.003 before 1.004 for Perl write past the end of the row buffer reading a PNG with a tRNS transparency chunk in read_direct8. With a tRNS chunk, read_direct8() adds an alpha channel to the image it creates but still sizes the row buffer from the original channel count. libpng expands the transparency into that extra channel, so png_read_row() fills one channel more than the buffer holds, at one byte per sample, and writes width bytes past the end of the allocation. Palette images go to read_paletted() and 16-bit images to read_direct16(), which sizes its buffer from png_get_rowbytes() and allocates enough for the expanded row. The same reader ships bundled in the Imager distribution. Reading an attacker-supplied PNG through Imager-\u003eread() corrupts the heap, which can crash the process.",
"id": "UBUNTU-CVE-2026-73639",
"modified": "2026-09-23T23:34:44Z",
"published": "2026-09-17T22:17:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2026-73639"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-73639"
},
{
"type": "REPORT",
"url": "https://github.com/tonycoz/imager/security/advisories/GHSA-jhx5-34j8-9g88"
},
{
"type": "REPORT",
"url": "https://github.com/tonycoz/imager/pull/567"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "medium",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2026-73639"
]
}
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