CVE-2026-112007

Schism Tracker through 20260524 contains a heap out-of-bounds write vulnerability in fmt_ult_load_song() in fmt/ult.c that fails to clamp the one-byte sample count to MAX_SAMPLES. Attackers can supply a crafted .ult module that overwrites the instruments pointer array, causing csf_destroy() to free attacker-chosen pointers and crash the application.

CVSS 4.0

6.9CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

6.1CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H

EPSS

0.1% chance of exploitation in the next 30 days; higher than 2% of CVEs (scores of 2026-10-25)

CWE

CWE-787

Published

2026-10-18

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

References

• https://github.com/schismtracker/schismtracker
• https://github.com/schismtracker/schismtracker/blob/74215ae300b555928332e03152dfcdc898f96ca6/fmt/ult.c#L319-L330
• https://hackmd.io/@haindpwn/schismtracker-ult-sample-count-oob-write
• https://www.vulncheck.com/advisories/schism-tracker-through-20260524-heap-out-of-bounds-write-via-ult-loader

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