DEBIAN-CVE-2026-47734
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 serve
DEBIAN-CVE-2026-47734
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-47734
dulwich
Source reference: /affected/0/package/name
- Affected versions
- 0.21.2-1
Source reference:
/affected/0/versions0.21.5-1Source reference:
/affected/0/versions0.21.6-1Source reference:
/affected/0/versions0.22.5-1Source reference:
/affected/0/versions0.22.7-1Source reference:
/affected/0/versions0.22.7-2Source reference:
/affected/0/versions0.24.10-1Source reference:
/affected/0/versions0.24.2-1Source reference:
/affected/0/versions0.24.2-2Source reference:
/affected/0/versions1.0.0-1Source reference:
/affected/0/versions1.0.0-2Source reference:
/affected/0/versions1.1.0-1Source reference:
/affected/0/versions1.1.0-2Source reference:
/affected/0/versions1.1.0-3Source reference:
/affected/0/versions1.2.0-1Source reference:
/affected/0/versions1.2.1-1Source reference:
/affected/0/versions1.2.11-1Source reference:
/affected/0/versions1.2.12-1Source reference:
/affected/0/versions1.2.5-1Source reference:
/affected/0/versions1.2.7-1Source reference:
/affected/0/versions1.2.7-2Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
dulwich
Source reference: /affected/1/package/name
- Affected versions
- 0.22.7-1
Source reference:
/affected/1/versions0.22.7-2Source reference:
/affected/1/versions0.24.10-1Source reference:
/affected/1/versions0.24.2-1Source reference:
/affected/1/versions0.24.2-2Source reference:
/affected/1/versions1.0.0-1Source reference:
/affected/1/versions1.0.0-2Source reference:
/affected/1/versions1.1.0-1Source reference:
/affected/1/versions1.1.0-2Source reference:
/affected/1/versions1.1.0-3Source reference:
/affected/1/versions1.2.0-1Source reference:
/affected/1/versions1.2.1-1Source reference:
/affected/1/versions1.2.11-1Source reference:
/affected/1/versions1.2.12-1Source reference:
/affected/1/versions1.2.5-1Source reference:
/affected/1/versions1.2.7-1Source reference:
/affected/1/versions1.2.7-2Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
dulwich
Source reference: /affected/2/package/name
- Affected versions
- 0.22.7-1
Source reference:
/affected/2/versions0.22.7-2Source reference:
/affected/2/versions0.24.10-1Source reference:
/affected/2/versions0.24.2-1Source reference:
/affected/2/versions0.24.2-2Source reference:
/affected/2/versions1.0.0-1Source reference:
/affected/2/versions1.0.0-2Source reference:
/affected/2/versions1.1.0-1Source reference:
/affected/2/versions1.1.0-2Source reference:
/affected/2/versions1.1.0-3Source reference:
/affected/2/versions1.2.0-1Source reference:
/affected/2/versions1.2.1-1Source reference:
/affected/2/versions - Fixed versions
- 1.2.5-1
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "dulwich",
"purl": "pkg:deb/debian/dulwich?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"0.21.2-1",
"0.21.5-1",
"0.21.6-1",
"0.22.5-1",
"0.22.7-1",
"0.22.7-2",
"0.24.10-1",
"0.24.2-1",
"0.24.2-2",
"1.0.0-1",
"1.0.0-2",
"1.1.0-1",
"1.1.0-2",
"1.1.0-3",
"1.2.0-1",
"1.2.1-1",
"1.2.11-1",
"1.2.12-1",
"1.2.5-1",
"1.2.7-1",
"1.2.7-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-47734.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "dulwich",
"purl": "pkg:deb/debian/dulwich?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"0.22.7-1",
"0.22.7-2",
"0.24.10-1",
"0.24.2-1",
"0.24.2-2",
"1.0.0-1",
"1.0.0-2",
"1.1.0-1",
"1.1.0-2",
"1.1.0-3",
"1.2.0-1",
"1.2.1-1",
"1.2.11-1",
"1.2.12-1",
"1.2.5-1",
"1.2.7-1",
"1.2.7-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-47734.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.2.5-1"
}
]
}
],
"package": {
"name": "dulwich",
"purl": "pkg:deb/debian/dulwich?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"0.22.7-1",
"0.22.7-2",
"0.24.10-1",
"0.24.2-1",
"0.24.2-2",
"1.0.0-1",
"1.0.0-2",
"1.1.0-1",
"1.1.0-2",
"1.1.0-3",
"1.2.0-1",
"1.2.1-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-47734.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #57143 · Revision 1
- Added to Heist Feed
- Publisher date