CVE-2026-73639
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
Published Sep 17, 2026
CVSS 3.1 · 9.1 Critical
EPSS < 1%
KEV · Not listed
Description
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->read() corrupts the heap, which can crash the process.
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 Products
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CVE record
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NVD configurations
No data
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Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
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| unaffected |
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| Vendor | Product | Versions | ||||||||
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| Tonyc | Imager::file::png |
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Remediation
Vendor Solution
Upgrade to Imager-File-PNG 1.004 or later, or to Imager 1.035 or later if the bundled copy is in use.
Tracking
Advisories
Metrics
No CVSS v4.0
Attack Vector Network
Attack Complexity Low
Privileges Required None
Scope Unchanged
Confidentiality Impact High
Integrity Impact None
Availability Impact High
User Interaction None
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.702% probability within 30 days)
Exploitation none
Automatable yes
Technical Impact partial
References
History
Sep 22, 2026 7:30 PM
Scoring metrics updated
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cvssV3_1
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Sep 18, 2026 9:30 PM
First appearance in the feed. Affected vendors updated
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| First Time appeared |
Tonyc
Tonyc imager::file::png |
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| Vendors & Products |
Tonyc
Tonyc imager::file::png |
Sep 18, 2026 1:30 AM
Added references
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| References |
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Sep 17, 2026 9:30 PM
Description updated. Title updated. Weaknesses updated. Added references
View changes
| Type | Values Removed | Values Added |
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| Description | 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->read() corrupts the heap, which can crash the process. | |
| Title | 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 | |
| Weaknesses | CWE-787 | |
| References |
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Subscriptions
Weaknesses
