CVE-2026-4426
A flaw was found in libarchive. An Undefined Behavior vulnerability exists in the zisofs decompression logic, caused by improper validation
CVSS
6.5
Medium
EPSS
0.3%
p23
KEV
—
Exploit Today
7
0-100
Published: Mar 19, 2026 · Last modified: Aug 31, 2026 · CWE-1335
0.3%EPSS · 30 days0.3%
2026-08-032026-08-31
A flaw was found in libarchive. An Undefined Behavior vulnerability exists in the zisofs decompression logic, caused by improper validation of a field (`pz_log2_bs`) read from ISO9660 Rock Ridge extensions. A remote attacker can exploit this by supplying a specially crafted ISO file. This can lead to incorrect memory allocation and potential application crashes, resulting in a denial-of-service (DoS) condition.
CVECVSSEPSSKEVRExploitTitleMod.
CVE-2026-50726.5 MED22.2%
——7A bitwise shift vulnerability in Zephyr's PTP subsystem allows a remote attacker to cause undefined behavior and potential system crashes. An attacker sends a crafted PTP_MSG_MANAGEMENT message to set an unvalidated negative log_announce_interval value in the port's data set. When a subsequent PTP_MSG_ANNOUNCE message is processed, port_timer_set_timeout_random computes a timeout as NSEC_PER_SEC >> -log_seconds; if the attacker-supplied value is sufficiently negative (e.g., -127), the shift amount exceeds the 64-bit integer width, triggering undefined behavior in C. This can cause a system crash via a compiler-generated illegal instruction trap on some architectures, or produce an erroneous zero timeout leading to resource starvation loops or other logical errors.40dCVE-2023-528107.8 HIG17.3%
——5In the Linux kernel, the following vulnerability has been resolved:
fs/jfs: Add check for negative db_l2nbperpage
l2nbperpage is log2(number of blks per page), and the minimum legal
value should be 0, not negative.
In the case of l2nbperpage being negative, an error will occur
when subsequently used as shift exponent.
Syzbot reported this bug:
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:799:12
shift exponent -16777216 is negative28dCVE-2016-98428.8 HIG91.9%
——28The inflateMark function in inflate.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact via vectors involving left shifts of negative integers.49d