{ "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": "2026-06-11T16:14:16.785Z" }, "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" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-06-11T14:08:10.796596Z", "id": "CVE-2026-47734", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-11T16:14:16.785Z" } } ] } }