Upstream information
Description
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.SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having moderate severity.
| CVSS detail | CNA (GitHub) | SUSE |
|---|---|---|
| Base Score | 5.7 | 6.5 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network | Network |
| Attack Complexity | Low | Low |
| Privileges Required | Low | Low |
| User Interaction | Required | None |
| Scope | Unchanged | Unchanged |
| Confidentiality Impact | None | None |
| Integrity Impact | None | None |
| Availability Impact | High | High |
| CVSSv3 Version | 3.1 | 3.1 |
Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Linux Enterprise Desktop 15 SP7 | python3-dulwich | Affected |
| SUSE Linux Enterprise High Performance Computing 12 | python-dulwich | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | python3-dulwich | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | python3-dulwich | Affected |
| SUSE Linux Enterprise Server 15 SP7 | python3-dulwich | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | python3-dulwich | Affected |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 15 SP4 | python3-dulwich | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | python3-dulwich | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | python3-dulwich | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | python3-dulwich | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | python3-dulwich | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | python3-dulwich | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | python3-dulwich | Affected |
| SUSE Linux Enterprise Module for Public Cloud 12 | python-dulwich | Affected |
| SUSE Linux Enterprise Server 12 SP5 | python-dulwich | Affected |
| SUSE Linux Enterprise Server 15 SP4 | python3-dulwich | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | python3-dulwich | Affected |
| SUSE Linux Enterprise Server 15 SP5 | python3-dulwich | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | python3-dulwich | Affected |
| SUSE Linux Enterprise Server 15 SP6 | python3-dulwich | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | python3-dulwich | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP5 | python-dulwich | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | python3-dulwich | Affected |
| SUSE Manager Proxy 4.3 | python3-dulwich | Affected |
| SUSE Manager Proxy LTS 4.3 | python3-dulwich | Affected |
| SUSE Manager Retail Branch Server 4.3 | python3-dulwich | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | python3-dulwich | Affected |
| SUSE Manager Server 4.3 | python3-dulwich | Affected |
| SUSE Manager Server LTS 4.3 | python3-dulwich | Affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE Linux Enterprise Desktop 15 SP4 | python3-dulwich | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | python3-dulwich | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | python3-dulwich | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | python3-dulwich | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | python3-dulwich | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | python3-dulwich | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | python3-dulwich | Affected |
| SUSE Linux Enterprise Server 12 | python-dulwich | Affected |
| SUSE Linux Enterprise Server 12 SP3 | python-dulwich | Affected |
| SUSE Linux Enterprise Server 12 SP4 | python-dulwich | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 | python-dulwich | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP3 | python-dulwich | Affected |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | python-dulwich | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | python3-dulwich | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | python3-dulwich | Affected |
| openSUSE Leap 15.4 | python3-dulwich | Affected |
| openSUSE Leap 15.5 | python3-dulwich | Affected |
| openSUSE Leap 15.6 | python3-dulwich | Affected |
SUSE Timeline for this CVE
CVE page created: Thu Jun 11 02:01:25 2026CVE page last modified: Thu Jun 11 17:26:01 2026