
libgit2 can face Denial of Service via heap out-of-bounds read from malicious Git servers (CVE-2026-53587). Is input validation sufficient protection for all external SCM data? #Git #CVE #SCM #OpenSource
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NVD description
libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, libgit2 performs a fixed-size strncmp in set_data in src/libgit2/transports/smart_pkt.c without first verifying that the smart-protocol pkt-line capability buffer contains 14 bytes. A malicious Git server can make bytes after the pkt-line complete object-format=, causing format_str to advance beyond the pkt-line and the following memchr length calculation to underflow. The resulting heap out-of-bounds walk can crash a client during the first refs-advertisement packet over HTTP, HTTPS, SSH, or the Git protocol. This issue is fixed in versions 1.8.6 and 1.9.5.
Priority
LOW
Exploitation
NONE
PoC
NONE
Patch
NONE
Momentum
NONE

libgit2 can face Denial of Service via heap out-of-bounds read from malicious Git servers (CVE-2026-53587). Is input validation sufficient protection for all external SCM data? #Git #CVE #SCM #OpenSource