Bug 2513487 (CVE-2026-18370)

Summary: CVE-2026-18370 entr: entr: Heap-based buffer overflow leads to denial of service
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in entr. A local attacker can exploit a heap-based buffer overflow in the `run_utility()` function by supplying specially crafted command-line arguments or using the `/_` substitution feature. This can lead to memory corruption, causing a process abort and a denial of service (DoS).
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Description OSIDB Bzimport 2026-08-10 13:01:26 UTC 
entr is vulnerable to Heap-based buffer overflow in run_utility() function. The function allocates a fixed-size heap buffer using malloc(ARG_MAX) and copies command-line arguments into it. It advances the destination pointer based on the return value of strlcpy(), which returns the total length of the source string rather than the number of bytes written. When the buffer is exactly filled, the remaining size underflows as an unsigned size_t, causing subsequent copies to write out of bounds. This can be triggered by supplying command-line arguments whose combined length fills the buffer, or via the /_ substitution feature which expands a short token into a longer pathname at runtime. The local attacker can cause memory corruption, process abort, and denial of service. 


This issue was fixed in commit 2467fe0