Summary
Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-78662: Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection. Now, we add an atomic established state, set when a channel becomes usable. Until such a time, handlePacket drops every packet other than the open confirmation/failure, without blocking and without tearing down the connection. CVE-2026-75593: BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to 0.31.2, a custom client can produce such an upload request to the BuildKit daemon that files can escape from the BuildKit-controlled state directory. The client needs to have valid permissions to access BuildKit control API to issue builds, eg., bypass authentication, etc. This issue is fixed in version 0.31.2. CVE-2026-61712: BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to 0.31.1, BuildKit read attacker-controlled /etc/passwd and /etc/group files without an upper bound while resolving a username to a user identifier or group identifier in executor/oci/user.go and solver/llbsolver/ops/user_linux.go. A malicious base image or build could provide oversized files that exhausted memory during user resolution and caused out-of-memory termination of the buildkitd process. This issue is fixed in version 0.31.1. CVE-2026-61711: BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to 0.31.1, a custom frontend could place an invalid SecurityMode value in a crafted build request, and executor/oci/spec_linux.go treated the unsupported value as a non-sandbox mode without requiring the security.insecure entitlement. This disabled Seccomp and AppArmor protections for the build container even though Linux capabilities remained restricted. This issue is fixed in version 0.31.1. CVE-2026-56855: Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking. CVE-2026-47262: Memory exhaustion DoS causing OOM kill of containerd process NOTE: https://github.com/containerd/containerd/security/advisories/GHSA-jpcc-p29g-p8mq CVE-2026-17106: The tar extraction routines in moby/go-archive (Unpack, UnpackLayer, Untar/UntarUncompressed, and the ApplyLayer helpers) do not confine filesystem operations to the destination directory. A crafted archive can create or overwrite files outside the intended destination. CVE-2026-15793: BuildKit custom frontends or clients using the raw low-level API can set git.checkoutbundle=true when checking out Git sources. If the Git source is malicious, this could lead to a crafted command invocation on the host. CVE-2026-15792: A malicious BuildKit client or frontend could craft a request that could lead to BuildKit daemon crashing with a panic. CVE-2026-15791: A crafted message in the BuildKit low-level build API can be used to remove the contents of the /tmp directory. The action that can normally be used to delete files inside the build container rootfs can escape into the real host temp directory. CVE-2026-15789: A custom client can produce such an upload request to the BuildKit daemon that files can escape from the BuildKit-controlled state directory. The client needs to have valid permissions to access the BuildKit control API to issue builds, e.g., bypass authentication, etc.
Fixed packages 1
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2023 | runfinch-finch | 0:1.19.0-1.amzn2023.0.1 |
Vulnerabilities 11
-
High 7.5
Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh
Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a…
-
High 7.5
Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh
Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection. Now, we add an atomic established state, set when a channel become…
-
High 7.2
BuildKit: Malicious client can bypass destination directory validation on local sources upload
BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to 0.31.2, a custom client can produce such an upload request to the BuildKit daemon that files can escape from the BuildKit-controlle…
-
High 7.1CVE-2026-17106 Public exploit
Tar extraction in moby/go-archive can write outside the destination directory via link following
The tar extraction routines in moby/go-archive (Unpack, UnpackLayer, Untar/UntarUncompressed, and the ApplyLayer helpers) do not confine filesystem operations to the destination directory. The extractor decides where each archive entry lands using lexical str…
-
Medium 6.9
Malicious client can bypass destination directory validation on local sources upload
A custom client can produce such an upload request to the BuildKit daemon that files can escape from the BuildKit-controlled state directory. The client needs to have valid permissions to access the BuildKit control API to issue builds, e.g., bypass authentic…
-
Medium 6.5
Git source checkout from a bundle file could lead to command injection
BuildKit custom frontends or clients using the raw low-level API can set git.checkoutbundle=true when checking out Git sources. If the Git source is malicious, this could lead to a crafted command invocation on the host.
-
Medium 6.3
Possible panic when incorrect parameters sent from frontend
A malicious BuildKit client or frontend could craft a request that could lead to BuildKit daemon crashing with a panic.
-
Medium 5.3
containerd image-triggered runtime DoS via unbounded group parsing
containerd is an open-source container runtime. Versions prior to 1.7.33, 2.0.10, 2.1.9, 2.2.5 and 2.3.2, contain a vulnerability that allows a maliciously crafted image to cause a Denial of Service (DoS) condition. When creating a container from this image, …
-
Medium 5.3
BuildKit: Custom frontend could bypass Seccomp/AppArmor
BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to 0.31.1, a custom frontend could place an invalid SecurityMode value in a crafted build request, and executor/oci/spec_linux.go trea…
-
Low 3.3
LLB file operation can be tricked to remove /tmp directory contents
A crafted message in the BuildKit low-level build API can be used to remove the contents of the /tmp directory. The action that can normally be used to delete files inside the build container rootfs can escape into the real host temp directory.
-
Low 2.3
BuildKit: Possible runtime DoS via unbounded group parsing
BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to 0.31.1, BuildKit read attacker-controlled /etc/passwd and /etc/group files without an upper bound while resolving a username to a u…
References
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-15789.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-15791.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-15792.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-15793.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-17106.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-47262.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-56855.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-61711.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-61712.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-75593.html
-
web
https://alas.aws.amazon.com/cve/html/CVE-2026-78662.html