CVE-2026-128991

Description

xschem 2.9.9 through 3.4.7 contains an out-of-bounds read vulnerability in read_xschem_file() in src/save.c that mishandles embedded-symbol records lacking a preceding instance. Attackers can supply a crafted schematic beginning with a "[" record, causing xschem to read and dereference memory below the instance array and crash.

References

• https://github.com/StefanSchippers/xschem
• https://github.com/StefanSchippers/xschem/blob/3.4.7/src/save.c#L3138-L3141
• https://github.com/StefanSchippers/xschem/commit/e29af39c6133c36bdaf66603fd663231e75517f1
• https://www.vulncheck.com/advisories/xschem-2.9.9-through-3.4.7-out-of-bounds-read-via-read-xschem-file-embedded-symbol-record