Amazon Linux 2 (EOS) Security Advisory: ALAS2DOCKER-2026-152
Advisory Released Date: 2026-10-24
Advisory Updated Date: 2026-10-26
FAQs regarding Amazon Linux ALAS/CVE Severity
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-2026-17106)
When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a "Trailer" header that declares a large number of fields causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits.
This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently.
Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits are now applied towards the trailer fields declared in "Trailer" headers.
NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9
NOTE: https://github.com/golang/go/issues/81857
NOTE: Fixed by: https://github.com/golang/go/commit/cbb0fb8b51cba866018b8a0fb4b5458f16c5c80b (go1.27.2)
NOTE: Fixed by: https://github.com/golang/go/commit/6e049521882c944afc1e519a83971ec421dc2974 (go1.26.9) (CVE-2026-78659)
When parsing a Range header containing a large number of small ranges, FileServer(FS), ServeContent, and ServeFile(FS) could consume an excessive amount of CPU.
These functions now ignore Range headers containing more than 200 ranges.
The limit is controlled by the new httpservecontentmaxranges=GODEBUG setting. Setting GODEBUG=httpservecontentmaxranges=0 disables the limit.
NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9
NOTE: https://github.com/golang/go/issues/81858
NOTE: Fixed by: https://github.com/golang/go/commit/ababc3cd873d8acce1777268aa7a817e6b672028 (go1.27.2)
NOTE: Fixed by: https://github.com/golang/go/commit/eb25b4e532c5a01f99ef860ec66743a8783f992b (go1.26.9) (CVE-2026-78667)
The firewall rules which mark VXLAN datagrams for encryption indiscriminately match both authentic VXLAN datagrams sent from the kernel and forged datagrams sent by user processes. Any packet sent from the host network namespace of a Linux Swarm node is encrypted with the overlay-network IPsec parameters which meets the following criteria:
- UDP datagram
- Destination port is the Swarm data-path port
- Datagram starts with a VXLAN header for the VNI of an encrypted overlay network which any running container on the node is connected to (CVE-2026-92542)
Docker Engine classifies a registry hostname as insecure using an any-match DNS check. loadInsecureRegistries() injects 127.0.0.0/8 and ::1/128 as insecure CIDRs by default. isCIDRMatch resolves all of the hostname's addresses and returns true if a single address is in the insecure CIDR list. Because the transport re-dials the hostname rather than the CIDR-matching address, a DNS answer set of one loopback IP plus a non-loopback attacker IP disables certificate verification and enables HTTP fallback for the registry connection. (CVE-2026-92543)
BuildKit may be tricked into performing file actions with special file inodes where regular files are expected. Special files may block operations or, on rootful workers, allow unintended host device access. (CVE-2026-93320)
Parsing a multipart form could bypass memory limits and read an arbitrarily long line into memory when the remaining limit at the start of a part was less than 400 bytes. Multipart form memory limits are now properly enforced in this situation.
NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9
NOTE: https://github.com/golang/go/issues/81741
NOTE: Fixed by: https://github.com/golang/go/commit/7c79b50a74b6d1aa4269b1827dda7d81f3717f9d (go1.27.2)
NOTE: Fixed by: https://github.com/golang/go/commit/d7a7aa8e6781ddf8dce12adf60a813d957d4763e (go1.26.9) (CVE-2026-94440)
Affected Packages:
docker
Note:
This advisory is applicable to Amazon Linux 2 - Docker Extra. Visit this page to learn more about Amazon Linux 2 (AL2) Extras and this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update docker or yum update --advisory ALAS2DOCKER-2026-152 to update your system.
aarch64:
docker-25.0.18-1.amzn2.0.1.aarch64
docker-debuginfo-25.0.18-1.amzn2.0.1.aarch64
src:
docker-25.0.18-1.amzn2.0.1.src
x86_64:
docker-25.0.18-1.amzn2.0.1.x86_64
docker-debuginfo-25.0.18-1.amzn2.0.1.x86_64