CVE-2026-110602

libmspack through 0.11alpha contains an uninitialized pointer free vulnerability in kwajd_open() in mspack/kwajd.c that frees unzeroed filename and extra pointers on header read errors. Attackers can supply a truncated, empty, or wrong-signature KWAJ file to crash the process or obtain an arbitrary-free memory corruption primitive.

CVSS 4.0

5.8CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

6.3CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 14% of CVEs (scores of 2026-10-25)

CWE

CWE-824

Published

2026-10-14

Modified

2026-10-16

Record from

the NVD, synced 2026-10-19

References

• https://github.com/kyz/libmspack/blob/v0.11alpha/libmspack/mspack/kwajd.c#L111-L181
• https://github.com/kyz/libmspack/commit/4d868504114346aa767d435fbb89a8b76603493f
• https://hackmd.io/@haind-pwn/libmspack-kwaj-uninitialized-free
• https://www.vulncheck.com/advisories/libmspack-through-0-11alpha-uninitialized-pointer-free-via-kwajd-open-error-path
• https://hackmd.io/@haind-pwn/libmspack-kwaj-uninitialized-free

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