{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-47734", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-05-19T22:16:39.503Z", "datePublished": "2026-06-10T22:11:02.704Z", "dateUpdated": "2026-06-10T22:11:02.704Z"}, "containers": {"cna": {"title": "Dulwich has unbounded memory allocation in receive-pack from crafted thin packs", "problemTypes": [{"descriptions": [{"cweId": "CWE-400", "lang": "en", "description": "CWE-400: Uncontrolled Resource Consumption", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-789", "lang": "en", "description": "CWE-789: Memory Allocation with Excessive Size Value", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/jelmer/dulwich/security/advisories/GHSA-xrvj-v92f-53gj", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/jelmer/dulwich/security/advisories/GHSA-xrvj-v92f-53gj"}, {"name": "https://github.com/jelmer/dulwich/releases/tag/dulwich-1.2.5", "tags": ["x_refsource_MISC"], "url": "https://github.com/jelmer/dulwich/releases/tag/dulwich-1.2.5"}], "affected": [{"vendor": "jelmer", "product": "dulwich", "versions": [{"version": ">= 0.1.0, < 1.2.5", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-06-10T22:11:02.704Z"}, "descriptions": [{"lang": "en", "value": "Dulwich is a pure-Python implementation of the Git file formats and protocols. Starting in version 0.1.0 and prior to version 1.2.5, a client with push access could push a tiny crafted thin pack (~174 bytes)  whose delta header declares a huge   dest_size. When dulwich ingested it via  add_thin_pack / apply_delta, it would  allocate hundreds of MB of memory based on that attacker-controlled size, with no relationship to the actual bytes received. Operators running a Dulwich-based Git server that exposes git-receive-pack (i.e. accepts pushes) - for example via dulwich.server functionality, the HTTP  smart server, or anything built on ReceivePackHandler - are impacted. The issue is patched in 1.2.5. add_thin_pack now accepts a max_input_size keyword (bytes; 0/None = unlimited, matching git's semantics), and ReceivePackHandler reads receive.maxInputSize from the repository config and passes it through. Wire reads are counted and a PackInputTooLarge exception is raised once the cap is exceeded - equivalent to git index-pack --max-input-size. Users should upgrade to Dulwich 1.2.5 or later and set receive.maxInputSize in their server's repository config to a sane bound for their environment. On unpatched versions, receive.maxInputSize has no effect, so it cannot be used as a workaround. Until upgrading, operators should restrict dulwich-receive-pack (push) access to trusted, authenticated clients only, or disable it entirely on servers that only need to serve fetches and/or run the server under an OS-level memory limit (e.g. ulimit, cgroups/MemoryMax, or a container memory limit) so a malicious push is killed rather than taking down the host."}], "source": {"advisory": "GHSA-xrvj-v92f-53gj", "discovery": "UNKNOWN"}}}}