Sylabs

By the Year

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

Recent Sylabs Security Vulnerabilities

CVE	Date	Vulnerability	Products
CVE-2025-64750	Dec 02, 2025	LSM Label Write Bypass in SingularityCE <4.3.5 / SingularityPRO <4.1.11,4.3.5 SingularityCE and SingularityPRO are open source container platforms. Prior to SingularityCE 4.3.5 and SingularityPRO 4.1.11 and 4.3.5, if a user relies on LSM restrictions to prevent malicious operations then, under certain circumstances, an attacker can redirect the LSM label write operation so that it is ineffective. The attacker must cause the user to run a malicious container image that redirects the mount of /proc to the destination of a shared mount, either known to be configured on the target system, or that will be specified by the user when running the container. The attacker must also control the content of the shared mount, for example through another malicious container which also binds it, or as a user with relevant permissions on the host system it is bound from. This vulnerability is fixed in SingularityCE 4.3.5 and SingularityPRO 4.1.11 and 4.3.5.	Singularity
CVE-2023-30549	Apr 25, 2023	Apptainer <1.1 Use-After-Free via ext4 in apptainer-suid Apptainer is an open source container platform for Linux. There is an ext4 use-after-free flaw that is exploitable through versions of Apptainer < 1.1.0 and installations that include apptainer-suid < 1.1.8 on older operating systems where that CVE has not been patched. That includes Red Hat Enterprise Linux 7, Debian 10 buster (unless the linux-5.10 package is installed), Ubuntu 18.04 bionic and Ubuntu 20.04 focal. Use-after-free flaws in the kernel can be used to attack the kernel for denial of service and potentially for privilege escalation. Apptainer 1.1.8 includes a patch that by default disables mounting of extfs filesystem types in setuid-root mode, while continuing to allow mounting of extfs filesystems in non-setuid "rootless" mode using fuse2fs. Some workarounds are possible. Either do not install apptainer-suid (for versions 1.1.0 through 1.1.7) or set `allow setuid = no` in apptainer.conf. This requires having unprivileged user namespaces enabled and except for apptainer 1.1.x versions will disallow mounting of sif files, extfs files, and squashfs files in addition to other, less significant impacts. (Encrypted sif files are also not supported unprivileged in apptainer 1.1.x.). Alternatively, use the `limit containers` options in apptainer.conf/singularity.conf to limit sif files to trusted users, groups, and/or paths, and set `allow container extfs = no` to disallow mounting of extfs overlay files. The latter option by itself does not disallow mounting of extfs overlay partitions inside SIF files, so that's why the former options are also needed.	Singularity
CVE-2022-23538	Jan 17, 2023	Singularity SCS lib client leaks Auth header to S3 in multipart download github.com/sylabs/scs-library-client is the Go client for the Singularity Container Services (SCS) Container Library Service. When the scs-library-client is used to pull a container image, with authentication, the HTTP Authorization header sent by the client to the library service may be incorrectly leaked to an S3 backing storage provider. This occurs in a specific flow, where the library service redirects the client to a backing S3 storage server, to perform a multi-part concurrent download. Depending on site configuration, the S3 service may be provided by a third party. An attacker with access to the S3 service may be able to extract user credentials, allowing them to impersonate the user. The vulnerable multi-part concurrent download flow, with redirect to S3, is only used when communicating with a Singularity Enterprise 1.x installation, or third party server implementing this flow. Interaction with Singularity Enterprise 2.x, and Singularity Container Services (cloud.sylabs.io), does not trigger the vulnerable flow. We encourage all users to update. Users who interact with a Singularity Enterprise 1.x installation, using a 3rd party S3 storage service, are advised to revoke and recreate their authentication tokens within Singularity Enterprise. There is no workaround available at this time.	Singularity Container Services Library
CVE-2022-39237	Oct 06, 2022	Insecure Hash Algorithm in syslabs/sif SIF ref impl (pre-2.8.1) syslabs/sif is the Singularity Image Format (SIF) reference implementation. In versions prior to 2.8.1the `github.com/sylabs/sif/v2/pkg/integrity` package did not verify that the hash algorithm(s) used are cryptographically secure when verifying digital signatures. A patch is available in version >= v2.8.1 of the module. Users are encouraged to upgrade. Users unable to upgrade may independently validate that the hash algorithm(s) used for metadata digest(s) and signature hash are cryptographically secure.	Singularity Image Format
CVE-2021-33027	Jul 19, 2021	Sylabs Singularity Enterprise through 1.6.2 has Insufficient Entropy in a nonce. Sylabs Singularity Enterprise through 1.6.2 has Insufficient Entropy in a nonce.	Singularity
CVE-2021-33622	Jun 15, 2021	Sylabs Singularity 3.5.x and 3.6.x Sylabs Singularity 3.5.x and 3.6.x, and SingularityPRO before 3.5-8, has an Incorrect Check of a Function's Return Value.	Singularity Singularitypro
CVE-2021-32635	May 28, 2021	Singularity is an open source container platform Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.	Singularity
CVE-2021-29499	May 07, 2021	SIF is an open source implementation of the Singularity Container Image Format SIF is an open source implementation of the Singularity Container Image Format. The `siftool new` command and func siftool.New() produce predictable UUID identifiers due to insecure randomness in the version of the `github.com/satori/go.uuid` module used as a dependency. A patch is available in version >= v1.2.3 of the module. Users are encouraged to upgrade. As a workaround, users passing CreateInfo struct should ensure the `ID` field is generated using a version of `github.com/satori/go.uuid` that is not vulnerable to this issue.	Singularity Image Format
CVE-2021-29136	Apr 06, 2021	Open Container Initiative umoci before 0.4.7 allows attackers to overwrite arbitrary host paths via a crafted image Open Container Initiative umoci before 0.4.7 allows attackers to overwrite arbitrary host paths via a crafted image that causes symlink traversal when "umoci unpack" or "umoci raw unpack" is used.	Singularity
CVE-2020-15229	Oct 14, 2020	Singularity (an open source container platform) from version 3.1.1 through 3.6.3 has a vulnerability Singularity (an open source container platform) from version 3.1.1 through 3.6.3 has a vulnerability. Due to insecure handling of path traversal and the lack of path sanitization within `unsquashfs`, it is possible to overwrite/create any files on the host filesystem during the extraction with a crafted squashfs filesystem. The extraction occurs automatically for unprivileged (either installation or with `allow setuid = no`) run of Singularity when a user attempt to run an image which is a local SIF image or a single file containing a squashfs filesystem and is coming from remote sources `library://` or `shub://`. Image build is also impacted in a more serious way as it can be used by a root user, allowing an attacker to overwrite/create files leading to a system compromise, so far bootstrap methods `library`, `shub` and `localimage` are triggering the squashfs extraction. This issue is addressed in Singularity 3.6.4. All users are advised to upgrade to 3.6.4 especially if they use Singularity mainly for building image as root user. There is no solid workaround except to temporary avoid to use unprivileged mode with single file images in favor of sandbox images instead. Regarding image build, temporary avoid to build from `library` and `shub` sources and as much as possible use `--fakeroot` or a VM for that.	Singularity