ALAS2ECS-2026-147

References: CVE-2026-78663  CVE-2026-78667  CVE-2026-94439  CVE-2026-94448 
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

The HTTP/2 server could refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data.
A malicious client could exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.
The HTTP/2 server now waits to refund connection-level flow control for reset streams until after the request handler is complete.

NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9
NOTE: https://github.com/golang/go/issues/81743
NOTE: Fixed by: https://github.com/golang/go/commit/31dc9e2449e394439498142451627af52626d7c4 (go1.27.2)
NOTE: Fixed by: https://github.com/golang/go/commit/6e049521882c944afc1e519a83971ec421dc2974 (go1.26.9) (CVE-2026-78663)

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)

When an HTTP server handler sent a 2xx response to an HTTP/1 CONNECT request and returned without hijacking the connection, the server improperly continued to read and serve requests from the connection. Since a 2xx response to an HTTP/1 CONNECT converts the connection into a tunnel, the server should not treat the connection as continuing to contain HTTP.
The impact of this misbehavior is mostly limited to potential request smuggling, where an intermediate proxy considers the data on the connection to be tunneled and the server considers it to be HTTP.
The HTTP/1 server now always closes a connection after responding to a CONNECT request, regardless of the response status.

NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9
NOTE: https://github.com/golang/go/issues/81744
NOTE: Fixed by: https://github.com/golang/go/commit/e92229e24a387cc006a750af176b07a459ba71a1 (go1.27.2)
NOTE: Fixed by: https://github.com/golang/go/commit/087de1ff08ea620ac2f6ae26c939454cb793883a (go1.26.9) (CVE-2026-94439)

When a JavaScript template literal contains consecutive expressions, the context tracking state was not properly reset upon entering a new expression.
We now ensure that template-literal expression entries correctly reset context variables so all subsequent regular expression literals are accurately recognized and escaped.

NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9
NOTE: https://github.com/golang/go/issues/81821
NOTE: Fixed by: https://github.com/golang/go/commit/b26d150e6985f804826f4fcb1aa33aa81e700b52 (go1.27.2)
NOTE: Fixed by: https://github.com/golang/go/commit/e59c03e695f2eaa26e308f756c83773afb034e47 (go1.26.9) (CVE-2026-94448)

Issue Correction:
Run yum update oci-add-hooks or yum update --advisory ALAS2ECS-2026-147 to update your system.

New Packages:

aarch64:
    oci-add-hooks-0-0.12.20200504git325a340.amzn2.aarch64
    oci-add-hooks-debuginfo-0-0.12.20200504git325a340.amzn2.aarch64

src:
    oci-add-hooks-0-0.12.20200504git325a340.amzn2.src

x86_64:
    oci-add-hooks-0-0.12.20200504git325a340.amzn2.x86_64
    oci-add-hooks-debuginfo-0-0.12.20200504git325a340.amzn2.x86_64