CVE-2026-73639

9.1 CRITICAL 0.7% exploit odds Fix listed Memory safety

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data exposure, service disruption.
Exploit odds: 0.7% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-08-13 12:51 UTC ReservedThe CVE id was reserved by its CNA
2026-09-17 22:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-22 19:16 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.7% in the next 30 days (EPSS).
Severity: 9.1 CRITICAL (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-09-17 22:17 UTC
Last modified: 2026-09-22 19:16 UTC
Exploit probability: 0.7% · EPSS, next 30 days
Weakness: CWE-787 · Out-of-bounds write
Record status: Deferred

Attack profile CVSS 3.1 · 9.1

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2026-73639.md and follow it. Check whether this project is affected by CVE-2026-73639. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record