Bug 2489842 (CVE-2026-54417)

Summary: CVE-2026-54417 microtar: microtar: Denial of Service via crafted tar archive due to integer overflow
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in microtar. A remote attacker can exploit an integer overflow vulnerability in the `mtar_next()` function by providing a specially crafted tar archive. This can lead to an uncontrolled consumption of CPU resources, causing the affected process to enter an infinite loop and resulting in a Denial of Service (DoS).
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Bug Depends On: 2490695, 2490696    
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Description OSIDB Bzimport 2026-06-17 15:01:27 UTC 
An integer overflow in the mtar_next() function in src/microtar.c in rxi microtar 0.1.0 allows a remote attacker to cause a denial of service (uncontrolled CPU consumption / infinite loop) via a crafted tar archive. mtar_next() computes the offset to the next record as round_up(h.size, 512) + sizeof(mtar_raw_header_t) using 32-bit arithmetic. When the header size field is a multiple of 512 in the range 0xFFFFFC01-0xFFFFFE00 (e.g. 0xFFFFFE00), the addition wraps to 0, so mtar_next() seeks to the current record position instead of advancing. As a result, mtar_find() and any loop that iterates entries with mtar_next() repeat indefinitely over the same record, hanging the process at 100% CPU with no recovery.