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
Summary
| CVE | CVE-2026-73639 |
|---|---|
| State | PUBLISHED |
| Assigner | CPANSec |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-17 22:17:03 UTC |
| Updated | 2026-09-18 17:49:29 UTC |
| 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. |
Risk And Classification
EPSS: 0.001760000 probability, percentile 0.074510000 (date 2026-09-19)
Problem Types: CWE-787 | CWE-787 CWE-787 Out-of-bounds Write
There are no known software configurations currently associated with this CVE in NVD or the CVE Program record.
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.openwall.com/lists/oss-security/2026/09/17/6 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | |
| metacpan.org/release/TONYC/Imager-1.035/changes | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| metacpan.org/release/TONYC/Imager-File-PNG-1.004/changes | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| github.com/tonycoz/imager/security/advisories/GHSA-jhx5-34j8-9g88 | 9b29abf9-4ab0-4765-b253-1875cd9b441e | github.com | |
| github.com/tonycoz/imager/pull/567 | 9b29abf9-4ab0-4765-b253-1875cd9b441e | github.com | |
| github.com/tonycoz/imager/commit/d973bd7e8843f084e8071caa24b89545c88b1e4... | 9b29abf9-4ab0-4765-b253-1875cd9b441e | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Alexander Bluhm (bluhm) (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-08-19T00:00:00.000Z | Imager-File-PNG 1.004 and Imager 1.035 released with fix. |
Solutions
CNA: Upgrade to Imager-File-PNG 1.004 or later, or to Imager 1.035 or later if the bundled copy is in use.
There are currently no legacy QID mappings associated with this CVE.