Netpbm contains an integer overflow in the jbigtopnm tool that is triggered when a crafted multi-plane JBIG file with an unusually large header provides dimensions that cause the computed output buffer size to exceed the allocated memory. The overflow occurs in the jbg_dec_merge_planes() routine and can lead to heap corruption, resulting in program crashes or potentially arbitrary code execution. This flaw is classified under CWE‑190, reflecting an integer overflow that is used to cause a buffer overflow.

The vulnerability affects the Netpbm software for all versions prior to 10.86.51, 11.x prior to 11.02.30, and 11.03 prior to 11.15.08. Users running these earlier releases are susceptible when processing JBIG files through jbigtopnm.

With a CVSS score of 8.5, the flaw is considered high severity. The EPSS score is not available, and the vulnerability is not currently listed in CISA’s KEV catalog. Inferred from the description, the likely attack vector is an attacker supplying a malicious JBIG file, which, if processed by jbigtopnm, could trigger the overflow. No additional exploitation prerequisites are stated, so the vulnerability is exploitable in any environment where Netpbm processes untrusted JBIG content.