CVE-2026-53587

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-53587
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53587.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-53587
Aliases
  • GHSA-pm24-4jhq-3xvm
Downstream
ALPINE (1)
ALSA (2)
AZL (1)
BELL (1)
CLSA (1)
DEBIAN (1)
ECHO (1)
JLSEC (1)
MGASA (1)
MINI (1)
openSUSE (1)
RHSA (6)
RLSA (2)
UBUNTU (1)
Related
ALSA (2)
openSUSE (1)
Published
2026-08-20T18:36:43Z
Modified
2026-10-28T11:09:50Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
libgit2 - Unauthenticated network-reachable heap out-of-bounds read in transports/smart_pkt.c:set_data
Details

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.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-125",
        "CWE-126",
        "CWE-1284",
        "CWE-20"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53587.json"
}
References

Affected packages

Git / github.com/libgit2/libgit2

Affected ranges

Type
GIT
Repo
https://github.com/libgit2/libgit2
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
5853918c4c6a7b12f8becf4bd11ff4362ebb9020
Introduced
338e6fb681369ff0537719095e22ce9dc602dbf0
Fixed
f7a4071c766ceea3915415e22134cbe3e581c420
Fixed
2c0ce8c0132ac38ab0db28239462a671e2e5440e
Fixed
affda60c10fcef16723451c0d7dc71b71dc20ad3
Fixed
d7a9fb87f504434e9f45228678953c4fa56e7640
Database specific
Show details 
{
    "extracted_events": [
        {
            "range": [
                {
                    "introduced": "0"
                },
                {
                    "fixed": "1.8.6"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "introduced": "1.9.0"
                },
                {
                    "fixed": "1.9.5"
                }
            ],
            "source": "AFFECTED_FIELD",
            "strategy": "StringRangeExpression"
        },
        {
            "range": [
                {
                    "fixed": "2c0ce8c0132ac38ab0db28239462a671e2e5440e"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "range": [
                {
                    "fixed": "affda60c10fcef16723451c0d7dc71b71dc20ad3"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "range": [
                {
                    "fixed": "d7a9fb87f504434e9f45228678953c4fa56e7640"
                }
            ],
            "source": "REFERENCES_COMMIT"
        },
        {
            "original_tag": "v1.8.6",
            "range": [
                {
                    "fixed": "5853918c4c6a7b12f8becf4bd11ff4362ebb9020"
                }
            ],
            "source": "REFERENCES_TAG"
        },
        {
            "original_tag": "v1.9.5",
            "range": [
                {
                    "fixed": "f7a4071c766ceea3915415e22134cbe3e581c420"
                }
            ],
            "source": "REFERENCES_TAG"
        }
    ]
}

Affected versions

v0.*
v0.1.0
v0.10.0
v0.11.0
v0.12.0
v0.13.0
v0.14.0
v0.15.0
v0.16.0
v0.17.0
v0.18.0
v0.2.0
v0.21.0
v0.22.0
v0.22.0-rc1
v0.22.0-rc2
v0.23.0
v0.23.0-rc1
v0.23.0-rc2
v0.24.0
v0.24.0-rc1
v0.26.0
v0.26.0-rc1
v0.26.0-rc2
v0.27.0
v0.27.0-rc1
v0.27.0-rc2
v0.27.0-rc3
v0.28.0
v0.28.0-rc1
v0.3.0
v0.8.0
v0.99.0
v1.*
v1.0.0
v1.1.0
v1.2.0
v1.3.0
v1.4.0
v1.5.0
v1.6.1
v1.6.2
v1.6.3
v1.7.0
v1.8.0
v1.8.1
v1.8.3
v1.8.4
v1.8.5
v1.9.0
v1.9.1
v1.9.2
v1.9.3
v1.9.4

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53587.json"
vanir_signatures 
[
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "177057447943472058086633744144048853923",
                "251528568997499059294437311657068512347",
                "263233899593817864986485995768435296270",
                "118977050417539920786203167605572346572"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-53587-1ad3cda7",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libgit2/libgit2/commit/d7a9fb87f504434e9f45228678953c4fa56e7640",
        "target": {
            "file": "src/libgit2/transports/smart_pkt.c"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "200721615194512407914353922973112910719",
            "length": 1230
        },
        "id": "CVE-2026-53587-7240f0e4",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libgit2/libgit2/commit/affda60c10fcef16723451c0d7dc71b71dc20ad3",
        "target": {
            "file": "src/libgit2/transports/smart_pkt.c",
            "function": "set_data"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "177057447943472058086633744144048853923",
                "251528568997499059294437311657068512347",
                "129832296391823552556717622608358726660",
                "112216264362753484961119941099410836764"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-53587-78ef06aa",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libgit2/libgit2/commit/2c0ce8c0132ac38ab0db28239462a671e2e5440e",
        "target": {
            "file": "src/libgit2/transports/smart_pkt.c"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "200721615194512407914353922973112910719",
            "length": 1230
        },
        "id": "CVE-2026-53587-97056e87",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libgit2/libgit2/commit/d7a9fb87f504434e9f45228678953c4fa56e7640",
        "target": {
            "file": "src/libgit2/transports/smart_pkt.c",
            "function": "set_data"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "173194287901579505293439928511578045548",
            "length": 1119
        },
        "id": "CVE-2026-53587-9efce08d",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/libgit2/libgit2/commit/2c0ce8c0132ac38ab0db28239462a671e2e5440e",
        "target": {
            "file": "src/libgit2/transports/smart_pkt.c",
            "function": "set_data"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "177057447943472058086633744144048853923",
                "251528568997499059294437311657068512347",
                "263233899593817864986485995768435296270",
                "118977050417539920786203167605572346572"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-53587-d2b13f5c",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/libgit2/libgit2/commit/affda60c10fcef16723451c0d7dc71b71dc20ad3",
        "target": {
            "file": "src/libgit2/transports/smart_pkt.c"
        }
    }
]
vanir_signatures_modified 
"2026-10-28T11:09:50Z"