Typelevel

By the Year

In 2026 there have been 0 vulnerabilities in Typelevel. Last year, in 2025 Typelevel had 1 security vulnerability published. Right now, Typelevel is on track to have less security vulnerabilities in 2026 than it did last year.

Recent Typelevel Security Vulnerabilities

CVE	Date	Vulnerability	Products
CVE-2025-58369	Sep 05, 2025	fs2 DoS in TLS via fs2.io.net.tls, vuln 2.5.12/3.12.2/3.13.0-M6, fixed 2.5.13/3.12.1/3.13.0-M7 fs2 is a compositional, streaming I/O library for Scala. Versions up to and including 2.5.12, 3.0.0-M1 through 3.12.2, and 3.13.0-M1 through 3.13.0-M6 are vulnerable to denial of service attacks though TLS sessions using fs2-io on the JVM using the fs2.io.net.tls package. When establishing a TLS session, if one side of the connection shuts down `write` while the peer side is awaiting more data to progress the TLS handshake, the peer side will spin loop on the socket read, fully utilizing a CPU. The CPU is consumed until the overall connection is closed, potentially shutting down a fs2-io powered server. This issue is fixed in versions 2.5.13, 3.12.1, and 3.13.0-M7.
CVE-2023-50730	Dec 22, 2023	StackOverflow via Cyclic Fragments / Deep Nesting in Grackle <0.18.0 Grackle is a GraphQL server written in functional Scala, built on the Typelevel stack. The GraphQL specification requires that GraphQL fragments must not form cycles, either directly or indirectly. Prior to Grackle version 0.18.0, that requirement wasn't checked, and queries with cyclic fragments would have been accepted for type checking and compilation. The attempted compilation of such fragments would result in a JVM `StackOverflowError` being thrown. Some knowledge of an applications GraphQL schema would be required to construct such a query, however no knowledge of any application-specific performance or other behavioural characteristics would be needed. Grackle uses the cats-parse library for parsing GraphQL queries. Prior to version 0.18.0, Grackle made use of the cats-parse `recursive` operator. However, `recursive` is not currently stack safe. `recursive` was used in three places in the parser: nested selection sets, nested input values (lists and objects), and nested list type declarations. Consequently, queries with deeply nested selection sets, input values or list types could be constructed which exploited this, causing a JVM `StackOverflowException` to be thrown during parsing. Because this happens very early in query processing, no specific knowledge of an applications GraphQL schema would be required to construct such a query. The possibility of small queries resulting in stack overflow is a potential denial of service vulnerability. This potentially affects all applications using Grackle which have untrusted users. Both stack overflow issues have been resolved in the v0.18.0 release of Grackle. As a workaround, users could interpose a sanitizing layer in between untrusted input and Grackle query processing.	Grackle
CVE-2023-22465	Jan 04, 2023	Http4s Header Parser Crash v0.1.0-0.21.34, 0.22.15, 0.23.17, 1.0.0-M38 Http4s is a Scala interface for HTTP services. Starting with version 0.1.0 and prior to versions 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38, the `User-Agent` and `Server` header parsers are susceptible to a fatal error on certain inputs. In http4s, modeled headers are lazily parsed, so this only applies to services that explicitly request these typed headers. Fixes are released in 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38. As a workaround, use the weakly typed header interface.	Http4s
CVE-2022-31183	Aug 01, 2022	fs2-io 3.1.0- Node TLSSocket server-mode requestCert ignored, mTLS bypass fs2 is a compositional, streaming I/O library for Scala. When establishing a server-mode `TLSSocket` using `fs2-io` on Node.js, the parameter `requestCert = true` is ignored, peer certificate verification is skipped, and the connection proceeds. The vulnerability is limited to: 1. `fs2-io` running on Node.js. The JVM TLS implementation is completely independent. 2. `TLSSocket`s in server-mode. Client-mode `TLSSocket`s are implemented via a different API. 3. mTLS as enabled via `requestCert = true` in `TLSParameters`. The default setting is `false` for server-mode `TLSSocket`s. It was introduced with the initial Node.js implementation of fs2-io in 3.1.0. A patch is released in v3.2.11. The requestCert = true parameter is respected and the peer certificate is verified. If verification fails, a SSLException is raised. If using an unpatched version on Node.js, do not use a server-mode TLSSocket with requestCert = true to establish a mTLS connection.	Fs2
CVE-2022-21653	Jan 05, 2022	Jawn is an open source JSON parser Jawn is an open source JSON parser. Extenders of the `org.typelevel.jawn.SimpleFacade` and `org.typelevel.jawn.MutableFacade` who don't override `objectContext()` are vulnerable to a hash collision attack which may result in a denial of service. Most applications do not implement these traits directly, but inherit from a library. `jawn-parser-1.3.1` fixes this issue and users are advised to upgrade. For users unable to upgrade override `objectContext()` to use a collision-safe collection.	Jawn
CVE-2021-41084	Sep 21, 2021	http4s is an open source scala interface for HTTP http4s is an open source scala interface for HTTP. In affected versions http4s is vulnerable to response-splitting or request-splitting attacks when untrusted user input is used to create any of the following fields: Header names (`Header.name`å), Header values (`Header.value`), Status reason phrases (`Status.reason`), URI paths (`Uri.Path`), URI authority registered names (`URI.RegName`) (through 0.21). This issue has been resolved in versions 0.21.30, 0.22.5, 0.23.4, and 1.0.0-M27 perform the following. As a matter of practice http4s services and client applications should sanitize any user input in the aforementioned fields before returning a request or response to the backend. The carriage return, newline, and null characters are the most threatening.	Http4s
CVE-2021-39185	Sep 01, 2021	Http4s is a minimal, idiomatic Scala interface for HTTP services Http4s is a minimal, idiomatic Scala interface for HTTP services. In http4s versions 0.21.26 and prior, 0.22.0 through 0.22.2, 0.23.0, 0.23.1, and 1.0.0-M1 through 1.0.0-M24, the default CORS configuration is vulnerable to an origin reflection attack. The middleware is also susceptible to a Null Origin Attack. The problem is fixed in 0.21.27, 0.22.3, 0.23.2, and 1.0.0-M25. The original `CORS` implementation and `CORSConfig` are deprecated. See the GitHub GHSA for more information, including code examples and workarounds.	Http4s
CVE-2021-32643	May 27, 2021	Http4s is a Scala interface for HTTP services Http4s is a Scala interface for HTTP services. `StaticFile.fromUrl` can leak the presence of a directory on a server when the `URL` scheme is not `file://`, and the URL points to a fetchable resource under its scheme and authority. The function returns `F[None]`, indicating no resource, if `url.getFile` is a directory, without first checking the scheme or authority of the URL. If a URL connection to the scheme and URL would return a stream, and the path in the URL exists as a directory on the server, the presence of the directory on the server could be inferred from the 404 response. The contents and other metadata about the directory are not exposed. This affects http4s versions: 0.21.7 through 0.21.23, 0.22.0-M1 through 0.22.0-M8, 0.23.0-M1, and 1.0.0-M1 through 1.0.0-M22. The [patch](https://github.com/http4s/http4s/commit/52e1890665410b4385e37b96bc49c5e3c708e4e9) is available in the following versions: v0.21.24, v0.22.0-M9, v0.23.0-M2, v1.0.0-M23. As a workaround users can avoid calling `StaticFile.fromUrl` with non-file URLs.	Http4s
CVE-2021-21294	Feb 02, 2021	Http4s (http4s-blaze-server) is a minimal, idiomatic Scala interface for HTTP services Http4s (http4s-blaze-server) is a minimal, idiomatic Scala interface for HTTP services. Http4s before versions 0.21.17, 0.22.0-M2, and 1.0.0-M14 have a vulnerability which can lead to a denial-of-service. Blaze-core, a library underlying http4s-blaze-server, accepts connections unboundedly on its selector pool. This has the net effect of amplifying degradation in services that are unable to handle their current request load, since incoming connections are still accepted and added to an unbounded queue. Each connection allocates a socket handle, which drains a scarce OS resource. This can also confound higher level circuit breakers which work based on detecting failed connections. http4s provides a general "MaxActiveRequests" middleware mechanism for limiting open connections, but it is enforced inside the Blaze accept loop, after the connection is accepted and the socket opened. Thus, the limit only prevents the number of connections which can be simultaneously processed, not the number of connections which can be held open. In 0.21.17, 0.22.0-M2, and 1.0.0-M14, a new "maxConnections" property, with a default value of 1024, has been added to the `BlazeServerBuilder`. Setting the value to a negative number restores unbounded behavior, but is strongly disrecommended. The NIO2 backend does not respect `maxConnections`. Its use is now deprecated in http4s-0.21, and the option is removed altogether starting in http4s-0.22. There are several possible workarounds described in the refrenced GitHub Advisory GHSA-xhv5-w9c5-2r2w.	Http4s
CVE-2021-21293	Feb 02, 2021	blaze is a Scala library for building asynchronous pipelines, with a focus on network IO blaze is a Scala library for building asynchronous pipelines, with a focus on network IO. All servers running blaze-core before version 0.14.15 are affected by a vulnerability in which unbounded connection acceptance leads to file handle exhaustion. Blaze, accepts connections unconditionally on a dedicated thread pool. This has the net effect of amplifying degradation in services that are unable to handle their current request load, since incoming connections are still accepted and added to an unbounded queue. Each connection allocates a socket handle, which drains a scarce OS resource. This can also confound higher level circuit breakers which work based on detecting failed connections. The vast majority of affected users are using it as part of http4s-blaze-server <= 0.21.16. http4s provides a mechanism for limiting open connections, but is enforced inside the Blaze accept loop, after the connection is accepted and the socket opened. Thus, the limit only prevents the number of connections which can be simultaneously processed, not the number of connections which can be held open. The issue is fixed in version 0.14.15 for "NIO1SocketServerGroup". A "maxConnections" parameter is added, with a default value of 512. Concurrent connections beyond this limit are rejected. To run unbounded, which is not recommended, set a negative number. The "NIO2SocketServerGroup" has no such setting and is now deprecated. There are several possible workarounds described in the refrenced GitHub Advisory GHSA-xmw9-q7x9-j5qc.	Blaze
CVE-2020-5280	Mar 25, 2020	http4s before versions 0.18.26, 0.20.20, and 0.21.2 has a local file inclusion vulnerability http4s before versions 0.18.26, 0.20.20, and 0.21.2 has a local file inclusion vulnerability. This vulnerability applies to all users of org.http4s.server.staticcontent.FileService, org.http4s.server.staticcontent.ResourceService and org.http4s.server.staticcontent.WebjarService. URI normalization is applied incorrectly. Requests whose path info contain ../ or // can expose resources outside of the configured location. This issue is patched in versions 0.18.26, 0.20.20, and 0.21.2. Note that 0.19.0 is a deprecated release and has never been supported.	Http4s