# Dulwich: Infinite Loop Denial of Service (DoS) in Packfile Object Resolution

Advisory record · `GHSA-35mr-4567-66vg`

- **Identifiers:** `GHSA-35mr-4567-66vg` · `CVE-2026-114095`
- **State:** Confirmed
- **Severity:** CVSS 7.1 High
- **Critical:** No
- **Weakness (CWE):** [CWE-835](https://cwe.mitre.org/data/definitions/835.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md)
- **Published:** 2 Oct 2026
- **Updated:** 21 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 2 Oct 2026, 18:54 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `dulwich` (PyPI): affected `<1.2.9`; fixed in `1.2.9`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Dulwich versions before 1.2.9 are vulnerable to a denial of service in the Pack.resolve_object method, which handles packfile object resolution. A malicious packfile containing an OFS_DELTA object with a delta offset of zero causes the resolver to recurse infinitely, consuming CPU until the process crashes. An attacker needs only to get a crafted packfile processed by an operation such as clone, fetch or cat-file. Upgrade to Dulwich 1.2.9 or later.

Written 1 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 7.1 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`, from CNA (VulnCheck)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0031, the 24th percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:08 UTC: First seen by agentprime
- 31 Oct 2026, 14:08 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-35mr-4567-66vg)

## Sources

- [GitHub Advisory Database: GHSA-35mr-4567-66vg](https://github.com/advisories/GHSA-35mr-4567-66vg)
- [OSV: GHSA-35mr-4567-66vg](https://osv.dev/vulnerability/GHSA-35mr-4567-66vg)
- <https://github.com/jelmer/dulwich/security/advisories/GHSA-35mr-4567-66vg>
- <https://github.com/jelmer/dulwich/commit/d06ffc3e1aff0ea0a32094debead891be0083eb7>
- <https://github.com/jelmer/dulwich>
- <https://github.com/jelmer/dulwich/releases/tag/dulwich-1.2.9>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-35mr-4567-66vg>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-35mr-4567-66vg/>. Everything for agents: <https://agentprime.io/llms.txt>.