Haskell Security Response Team - Announcement and Q2 2023 report

The Haskell Security Response Team (SRT) is a volunteer organization within the Haskell Foundation that is building tools and processes to aid the entire Haskell ecosystem in assessing and responding to
security risks. In particular, we maintain a database of security advisories that can serve as a data source for automated tooling.

This post announces the SRT membership and the commencement of our work, and also serves as our first quarterly report.

How to contact the SRT

For assistance in coordinating a security response to new, high impact vulnerabilities, contact security-advisories@haskell.org. Due to limited resources, we can only coordinate embargoed disclosures for high impact vulnerabilities affecting core Haskell tools and libraries. We’ll decide whether to offer this service on a case by case basis.

You can submit lower-impact or historical vulnerabilities to the advisory database via the pull request process. There are further details later in this report.

You can also contact the SRT about non-advisory/security-response topics. We prefer public communication where possible. In most cases, GitHub issues are an appropriate forum. But the mail address is there if no other appropriate channel exists.

SRT membership and kick-off

Fraser Tweedale volunteered to found the team, based on preparatory work done by the Haskell Foundation’s Technical Working Group. After he came up with an initial set of procedures and the group
structure, we posted a call for volunteers on February 9. We received many qualified applicants, and it was difficult to choose the initial committee. We tried to prioritize recruiting people with non-overlapping technical knowledge as well as substantial real-world experience managing security processes for open-source projects.

The members of the SRT are:

  • Casey Mattingly - Security Research Scientist at a large financial institution, responds to and manages CVEs and disclosures, experience with data-driven security governance processes, undergoes mandatory annual security trainings with employer, implemented three authentication frameworks
  • Fraser Tweedale - Principal Software Engineer at Red Hat working on PKI and identity management solutions. Organizer of the Haskell devroom at FOSDEM and regular speaker at conferences.
  • Gautier Di Folco - Haskeller for more than a decade, full-time for more than two years. Primarily responsible for his companies’ security policies. Prior experience in secure development in networking and telecommunications hardware as well as managing security for Web applications.
  • Mihai Maruseac - Stackage curator, contributor to Stack, former contributor to Haskell Communities and Activities Report, founder of the TensorFlow security team, member of Google Open Source Security Team
  • Tristan de Cacqueray - Principal Software Engineer at Red Hat. Six years of experience on the OpenStack Vulnerability Management Team; produced 56 advisories through this process, including technical analysis, public communication, and CVE assignment.

Additionally, David Thrane Christiansen, Executive Director of the Haskell Foundation, participates in meetings and helps connect the group to other Haskell projects.

The first meeting of the SRT was held on May 3. Most of us were strangers so we spent some time getting to know each others’ personalities, areas of expertise, and ways of working. Since then we’ve been busy preparing our tools and processes, refining our database format, and making contact with the broader open source security response ecosystem.


The SRT has a video-conference every 2 weeks. Meeting notes are published in the security-advisories repository (possibly with redactions). Technical discussion is primarily in (public) GitHub issues and pull requests. SRT process/management topics and embargoed vulnerabilities are discussed during our meetings and in a private mailing list.

Terms and recruitment

The initial terms of some SRT members will expire at the end of Q3. We have decided that members wishing to continue may do so. Closer to the end of Q3, we will consider whether we should grow the team. If we decide to do that, and/or there are casual vacancies, we will put out a new call for volunteers toward the end of Q3.

Technical work

Database is open for submissions.

The security-advisories database is open for submissions. So far, there are only a few historical vulnerabilities, which we used to test our tool code and submission processes.

We have a list of several known historical advisories (GitHub issue) still to be added. If you know of any others, please let us know in the issue (or write and submit the advisory yourself).

The submission process is detailed in CONTRIBUTING.md. If something goes wrong or the steps are not sufficiently clear, that is a bug; please let us know (e.g. create a GitHub issue).

If you want to submit a new, high-impact vulnerability, or would like SRT assistance to coordinate a response, please mail security-advisories@haskell.org with details instead of submitting a pull request (PRs are public). Rule of thumb: a high-severity vulnerability affecting the GHC toolchain or a popular library. If you think you might have a high-impact vulnerability, please contact the SRT and we will help to assess the impact.

The SRT has not adopted a means of end-to-end encrypted communication (e.g. OpenPGP) at this time.

Advisory format

The advisory format is Markdown with a TOML header containing metadata, such as affected packages/versions, CVSS scores, and references. The EXAMPLE_ADVISORY explains the header format.

The design followed RustSec’s advisory format. During our initial work, we made some changes to more closely align with the format used by OSV, a multi-language repository of security advisories. Many systems already read from OSV, making it even easier for the Haskell community to get value from these systems.

OSV Export

The native format of OSV is generated from our database and published on the generated/osv-export branch. This makes it easy for systems that understand OSV to consume our advisories.

We are working with the osv.dev project to get the HSEC source set up (see osv.dev issue #1418). As of early July, the OSV test instance is ingesting HSEC advisories (results).

Automation Improvements

We hope to enable a richer advisory contributor (and reviewer) experience through GitHub automation. Ideas are being gathered at pull request automation - ideation · Issue #57 · haskell/security-advisories · GitHub. Community input or contributions are welcome. If you have experience developing GitHub webhook applications, your contributions could be especially valuable.

Haskell Development

The hsec-tools library and executable live in the security-advisories database, alongside the advisories themselves. Our code is published under a BSD 3-Clause license.

In Q3 of 2023, we plan to extract the general-purpose OSV-related datatypes and utilities from our tools into a standalone package and release it separately on Hackage. We additionally plan to develop and release a library for processing CVSS scores.


We have rehearsed our processes by creating advisories for a number of already-known security issues in the Haskell ecosystem. This helped us uncover ways in which our tools, data formats, and processes were not quite ready. In addition to the resulting data being useful, we are now better prepared for incoming reports, whether confidential or public.

Future investigations

The Vulnerability Exploitable eXchange (VEX) data model describes the impact (or lack of) of some vulnerability in a particular program or component. The SRT plans to investigate VEX as a means to suppress false-positives where some dependency of a program/library contains a vulnerability, but that vulnerability is mitigated or not present at all in the dependent program.

VEX also requires “action statements” for affected programs, which are intended to convey possible mitigations, workarounds or remediations. Storing and conveying this kind of information in security tooling could further enhance the Haskell security tooling story.


If you’d like to make it easier for Haskell programmers to avoid security problems in dependencies, there are many concrete projects that would be very helpful! The SRT doesn’t have the capacity to take these tasks on, but we’re happy to advise.

  • Build plan auditing for cabal-install would allow users to be notified if their build plan depends on a package for which there is an advisory, similar to cargo audit or npm audit. In addition to their features, it could also be useful to additionally allow a specification of a threat model, so that advisories for attack vectors requiring network access would not be shown for offline-only applications.
  • A tool that scans Stackage snapshots for versions affected by advisories, notifying both users and the Stackage maintainers so that the snapshot can be updated
  • Integration with hackage-server, to indicate known-vulnerable package versions.
  • A tool for project maintainers to generate a skeleton advisory for their own project, parsing information out of the Cabal file and asking some convenient questions
  • Integration with other sources of advisories that don’t pull from OSV

Generally speaking, we’d like to support every effort to increase the value that the advisories provide to the Haskell ecosystem. However, it is not within the capacity or scope of the SRT to develop all the above ideas. Instead, we hope to collaborate with “downstream” projects, evolving both the database content and the associated tools and libraries to meet their needs.


We need an implementation of the TUF, so more tools can utilize it. The current implementation is not general enough:


Thanks for pointing this out. TUF is not in the (current) scope of SRT work. But it is an important part of the overall Haskell security posture!

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Wow, what a wonderful team of great people working on security in Haskell!

With such a membership, I have huge hopes for the outputs of this initiative. Good luck everyone and thanks for your outstanding work so far! :rocket:


Does the haskell security response team has a github group, so that it can more easily be contacted and pinged on github?

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You can create an issue in GitHub - haskell/security-advisories. We don’t have a team object in GitHub at this time.

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