{"id":"CVE-2026-73639","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.\n\nWith a tRNS chunk, read_direct8() adds an alpha channel to the image it creat…","summary":"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.\n\nWith a tRNS chunk, read_direct8() adds an alpha channel to the image it creat…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","cwe":["CWE-787"],"product":"Imager-File-PNG","affected":["Imager-File-PNG >= 1.003 < 1.004","Imager >= 1.034 < 1.035"],"published":"2026-09-17","updated":"2026-09-22","sourceUpdated":"2026-09-22T19:16:44.383","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-73639","references":[{"url":"https://github.com/tonycoz/imager/commit/d973bd7e8843f084e8071caa24b89545c88b1e4b.patch","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://github.com/tonycoz/imager/pull/567","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://github.com/tonycoz/imager/security/advisories/GHSA-jhx5-34j8-9g88","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/TONYC/Imager-1.035/changes","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/TONYC/Imager-File-PNG-1.004/changes","label":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"http://www.openwall.com/lists/oss-security/2026/09/17/6","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"epss":0.00176,"epssPercentile":0.07432,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-22T18:04:27.077498Z"},"ingestedAt":"2026-09-17T21:29:17.000Z","slug":"CVE-2026-73639","body":"## Overview\n\nImager::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.\n\nWith 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.\n\nThe same reader ships bundled in the Imager distribution.\n\nReading an attacker-supplied PNG through Imager->read() corrupts the heap, which can crash the process.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":209325,"id":"CVE-2026-73639","ts":1790104206172,"field":"cvss","old":null,"new":"9.1"},{"seq":209324,"id":"CVE-2026-73639","ts":1790104206172,"field":"severity","old":"none","new":"critical"}]}