CVE-2026-53587 in Canonical and Libgit2 Products
Published on August 20, 2026
libgit2 - Unauthenticated network-reachable heap out-of-bounds read in transports/smart_pkt.c:set_data
Vulnerability Analysis
CVE-2026-53587 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Types
Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
Out-of-bounds Read
The software reads data past the end, or before the beginning, of the intended buffer. Typically, this can allow attackers to read sensitive information from other memory locations or cause a crash. A crash can occur when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string. The expected sentinel might not be located in the out-of-bounds memory, causing excessive data to be read, leading to a segmentation fault or a buffer overflow. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent read operation then produces undefined or unexpected results.
Buffer Over-read
The software reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer. This typically occurs when the pointer or its index is incremented to a position beyond the bounds of the buffer or when pointer arithmetic results in a position outside of the valid memory location to name a few. This may result in exposure of sensitive information or possibly a crash.
Improper Validation of Specified Quantity in Input
The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.
Products Associated with CVE-2026-53587
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Affected Versions
libgit2:- Version < 1.8.6 is affected.
- Version >= 1.9.0, < 1.9.5 is affected.